Method and apparatus for indicating slot format of an unlicensed cell in a wireless communication system

ABSTRACT

A method and apparatus are disclosed from the perspective of a User Equipment (UE). In one embodiment, the method includes the UE performing transmission and/or reception in a serving cell, wherein the serving cell is in unlicensed spectrum. The method further includes the UE being configured to receive slot format indication (SFI) on periodic SFI monitoring occasion(s), wherein periodic SFI monitoring occasion(s) is (pre-)configured by a network. The method also includes the UE, in response to receiving and/or detecting a channel indicator, monitoring and/or detecting a first SFI-related signal on a first occasion, wherein the first occasion is not one of (pre-)configured periodic SFI monitoring occasion(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/527,777, filed Jul. 31, 2019, which claims priority to andthe benefit of U.S. Provisional Patent Application Ser. No. 62/712,597,filed Jul. 31, 2018, and U.S. Provisional Patent Application Ser. No.62/714,415, filed Aug. 3, 2018; with the entire disclosures of eachreferenced application fully incorporated herein by reference.

FIELD

This disclosure generally relates to wireless communication networks,and more particularly, to a method and apparatus for indicating slotformat of an unlicensed cell in a wireless communication system.

BACKGROUND

With the rapid rise in demand for communication of large amounts of datato and from mobile communication devices, traditional mobile voicecommunication networks are evolving into networks that communicate withInternet Protocol (IP) data packets. Such IP data packet communicationcan provide users of mobile communication devices with voice over IP,multimedia, multicast and on-demand communication services.

An exemplary network structure is an Evolved Universal Terrestrial RadioAccess Network (E-UTRAN). The E-UTRAN system can provide high datathroughput in order to realize the above-noted voice over IP andmultimedia services. A new radio technology for the next generation(e.g., 5G) is currently being discussed by the 3GPP standardsorganization. Accordingly, changes to the current body of 3GPP standardare currently being submitted and considered to evolve and finalize the3GPP standard.

SUMMARY

A method and apparatus are disclosed from the perspective of a UserEquipment (UE). In one embodiment, the method includes the UE performingtransmission and/or reception in a serving cell, wherein the servingcell is in unlicensed spectrum. The method further includes the UE beingconfigured to receive slot format indication (SFI) on periodic SFImonitoring occasion(s), wherein periodic SFI monitoring occasion(s) is(pre-)configured by a network. The method also includes the UE, inresponse to receiving and/or detecting a channel indicator, monitoringand/or detecting a first SFI-related signal on a first occasion, whereinthe first occasion is not one of (pre-)configured periodic SFImonitoring occasion(s).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of a wireless communication system according toone exemplary embodiment.

FIG. 2 is a block diagram of a transmitter system (also known as accessnetwork) and a receiver system (also known as user equipment or UE)according to one exemplary embodiment.

FIG. 3 is a functional block diagram of a communication system accordingto one exemplary embodiment.

FIG. 4 is a functional block diagram of the program code of FIG. 3according to one exemplary embodiment.

FIGS. 5A and 5B are a reproduction of Table 11.1.1-1 of 3GPP TS 38.213V15.2.0.

FIG. 6 is a reproduction of FIG. 1 of 3GPP R1-1806105.

FIG. 7 is a reproduction of FIG. 2 of 3GPP R1-1806105.

FIG. 8 is a reproduction of Table 7.3.1-1 of 3GPP TS 38.212 v15.2.0.

FIG. 9 is a reproduction of Table 15.1.1-1 of 3GPP TS 36.213 v15.1.0.

FIG. 10 is a diagram according to one exemplary embodiment.

FIG. 11 is a diagram according to one exemplary embodiment.

FIG. 12 is a diagram according to one exemplary embodiment.

FIG. 13 is a diagram according to one exemplary embodiment.

FIG. 14 is a diagram according to one exemplary embodiment.

FIG. 15 is a flow chart according to one exemplary embodiment.

FIG. 16 is a flow chart according to one exemplary embodiment.

FIG. 17 is a flow chart according to one exemplary embodiment.

FIG. 18 is a flow chart according to one exemplary embodiment.

FIG. 19 is a flow chart according to one exemplary embodiment.

FIG. 20 is a flow chart according to one exemplary embodiment.

FIG. 21 is a flow chart according to one exemplary embodiment.

FIG. 22 is a flow chart according to one exemplary embodiment.

FIG. 23 is a flow chart according to one exemplary embodiment.

FIG. 24 is a flow chart according to one exemplary embodiment.

FIG. 25 is a flow chart according to one exemplary embodiment.

FIG. 26 is a flow chart according to one exemplary embodiment.

FIG. 27 is a flow chart according to one exemplary embodiment.

FIG. 28 is a flow chart according to one exemplary embodiment.

DETAILED DESCRIPTION

The exemplary wireless communication systems and devices described belowemploy a wireless communication system, supporting a broadcast service.Wireless communication systems are widely deployed to provide varioustypes of communication such as voice, data, and so on. These systems maybe based on code division multiple access (CDMA), time division multipleaccess (TDMA), orthogonal frequency division multiple access (OFDMA),3GPP LTE (Long Term Evolution) wireless access, 3GPP LTE-A orLTE-Advanced (Long Term Evolution Advanced), 3GPP2 UMB (Ultra MobileBroadband), WiMax, 3GPP NR (New Radio), or some other modulationtechniques.

In particular, the exemplary wireless communication systems devicesdescribed below may be designed to support one or more standards such asthe standard offered by a consortium named “3rd Generation PartnershipProject” referred to herein as 3GPP, including: TS 38.213 V15.2.0,“Physical layer procedures for control”; TS 38.211 V15.2.0, “Physicalchannels and modulation”; Final Report of 3GPP TSG RAN WG1 #AH 1801v1.0.0 (Vancouver, Canada, 22-26 Jan. 2018); Final Report of 3GPP TSGRAN WG1 #92 v1.0.0 (Athens, Greece, 26 Feb.-2 Mar. 2018); Final Reportof 3GPP TSG RAN WG1 #92bis v1.0.0 (Sanya, China, 16-20 Apr. 2018); DraftReport of 3GPP TSG RAN WG1 #93 v0.2.0 (Busan, South Korea, 21-25 May2018); TS 38.331 V15.2.0, “Radio Resource Control (RRC) protocolspecification”; R1-1807386, “TxOP Frame Structure for NR unlicensed”,Qualcomm Incorporated; R1-1806105, “Frame structure for NR-U operation”,Nokia, Nokia Shanghai Bell; TS 38.212 V15.2.0, “Multiplexing and channelcoding”; TS 36.213 v15.1.0, “Physical layer procedures”; and TS 37.213v15.0.0, “Physical layer procedures for shared spectrum channel access”.The standards and documents listed above are hereby expresslyincorporated by reference in their entirety.

FIG. 1 shows a multiple access wireless communication system accordingto one embodiment of the invention. An access network 100 (AN) includesmultiple antenna groups, one including 104 and 106, another including108 and 110, and an additional including 112 and 114. In FIG. 1 , onlytwo antennas are shown for each antenna group, however, more or fewerantennas may be utilized for each antenna group. Access terminal 116(AT) is in communication with antennas 112 and 114, where antennas 112and 114 transmit information to access terminal 116 over forward link120 and receive information from access terminal 116 over reverse link118. Access terminal (AT) 122 is in communication with antennas 106 and108, where antennas 106 and 108 transmit information to access terminal(AT) 122 over forward link 126 and receive information from accessterminal (AT) 122 over reverse link 124. In a FDD system, communicationlinks 118, 120, 124 and 126 may use different frequency forcommunication. For example, forward link 120 may use a differentfrequency then that used by reverse link 118.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the access network. Inthe embodiment, antenna groups each are designed to communicate toaccess terminals in a sector of the areas covered by access network 100.

In communication over forward links 120 and 126, the transmittingantennas of access network 100 may utilize beamforming in order toimprove the signal-to-noise ratio of forward links for the differentaccess terminals 116 and 122. Also, an access network using beamformingto transmit to access terminals scattered randomly through its coveragecauses less interference to access terminals in neighboring cells thanan access network transmitting through a single antenna to all itsaccess terminals.

An access network (AN) may be a fixed station or base station used forcommunicating with the terminals and may also be referred to as anaccess point, a Node B, a base station, an enhanced base station, anevolved Node B (eNB), a network node, a network, or some otherterminology. An access terminal (AT) may also be called user equipment(UE), a wireless communication device, terminal, access terminal or someother terminology.

FIG. 2 is a simplified block diagram of an embodiment of a transmittersystem 210 (also known as the access network) and a receiver system 250(also known as access terminal (AT) or user equipment (UE)) in a MIMOsystem 200. At the transmitter system 210, traffic data for a number ofdata streams is provided from a data source 212 to a transmit (TX) dataprocessor 214.

In one embodiment, each data stream is transmitted over a respectivetransmit antenna. TX data processor 214 formats, codes, and interleavesthe traffic data for each data stream based on a particular codingscheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by processor 230.

The modulation symbols for all data streams are then provided to a TXMIMO processor 220, which may further process the modulation symbols(e.g., for OFDM). TX MIMO processor 220 then provides N_(T) modulationsymbol streams to N_(T) transmitters (TMTR) 222 a through 222 t. Incertain embodiments, TX MIMO processor 220 applies beamforming weightsto the symbols of the data streams and to the antenna from which thesymbol is being transmitted.

Each transmitter 222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transmitters 222 a through 222 t are thentransmitted from N_(T) antennas 224 a through 224 t, respectively.

At receiver system 250, the transmitted modulated signals are receivedby N_(R) antennas 252 a through 252 r and the received signal from eachantenna 252 is provided to a respective receiver (RCVR) 254 a through254 r. Each receiver 254 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 260 then receives and processes the N_(R) receivedsymbol streams from N_(R) receivers 254 based on a particular receiverprocessing technique to provide N_(T) “detected” symbol streams. The RXdata processor 260 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by RX data processor 260 is complementary to thatperformed by TX MIMO processor 220 and TX data processor 214 attransmitter system 210.

A processor 270 periodically determines which pre-coding matrix to use(discussed below). Processor 270 formulates a reverse link messagecomprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 238, whichalso receives traffic data for a number of data streams from a datasource 236, modulated by a modulator 280, conditioned by transmitters254 a through 254 r, and transmitted back to transmitter system 210.

At transmitter system 210, the modulated signals from receiver system250 are received by antennas 224, conditioned by receivers 222,demodulated by a demodulator 240, and processed by a RX data processor242 to extract the reserve link message transmitted by the receiversystem 250. Processor 230 then determines which pre-coding matrix to usefor determining the beamforming weights then processes the extractedmessage.

Turning to FIG. 3 , this figure shows an alternative simplifiedfunctional block diagram of a communication device according to oneembodiment of the invention. As shown in FIG. 3 , the communicationdevice 300 in a wireless communication system can be utilized forrealizing the UEs (or ATs) 116 and 122 in FIG. 1 or the base station (orAN) 100 in FIG. 1 , and the wireless communications system is preferablythe NR system. The communication device 300 may include an input device302, an output device 304, a control circuit 306, a central processingunit (CPU) 308, a memory 310, a program code 312, and a transceiver 314.The control circuit 306 executes the program code 312 in the memory 310through the CPU 308, thereby controlling an operation of thecommunications device 300. The communications device 300 can receivesignals input by a user through the input device 302, such as a keyboardor keypad, and can output images and sounds through the output device304, such as a monitor or speakers. The transceiver 314 is used toreceive and transmit wireless signals, delivering received signals tothe control circuit 306, and outputting signals generated by the controlcircuit 306 wirelessly. The communication device 300 in a wirelesscommunication system can also be utilized for realizing the AN 100 inFIG. 1 .

FIG. 4 is a simplified block diagram of the program code 312 shown inFIG. 3 in accordance with one embodiment of the invention. In thisembodiment, the program code 312 includes an application layer 400, aLayer 3 portion 402, and a Layer 2 portion 404, and is coupled to aLayer 1 portion 406. The Layer 3 portion 402 generally performs radioresource control. The Layer 2 portion 404 generally performs linkcontrol. The Layer 1 portion 406 generally performs physicalconnections.

3GPP TS 38.213 describes the following procedures for PDCCH monitoring,slot format, frame structure, bandwidth part (BWP), and someabbreviation. A slot format value could be 0 to 255 indicating an entryof Table 11.1.1-1 of 3GPP TS 38.213 V15.2.0 (reproduced as FIGS. 5A and5B). A slot format value could indicate a slot format of a slot withnormal cyclic prefix.

10 UE Procedure for Receiving Control Information

10.1 UE Procedure for Determining Physical Downlink Control ChannelAssignment

For each DL BWP configured to a UE in a serving cell, a UE can beprovided by higher layer signalling with P≤3 control resource sets. Foreach control resource set, the UE is provided the following by higherlayer parameter ControlResourceSet:

-   -   a control resource set index p, 0≤p<12, by higher layer        parameter controlResourceSetId;    -   a DM-RS scrambling sequence initialization value by higher layer        parameter pdcch-DMRS-ScramblingiD;    -   a precoder granularity for a number of REGs in the frequency        domain where the UE can assume use of a same DM-RS precoder by        higher layer parameter precoderGranularity;    -   a number of consecutive symbols provided by higher layer        parameter duration;    -   a set of resource blocks provided by higher layer parameter        frequencyDomainResources;    -   CCE-to-REG mapping parameters provided by higher layer parameter        cce-REG-MappingType;    -   an antenna port quasi co-location, from a set of antenna port        quasi co-locations provided by higher layer parameter        TCI-StatesPDCCH, indicating quasi co-location information of the        DM-RS antenna port for PDCCH reception;    -   an indication for a presence or absence of a transmission        configuration indication (TCI) field for DCI format 1_1        transmitted by a PDCCH in control resource set p, by higher        layer parameter TCI-PresentInDCI.

For each DL BWP configured to a UE in a serving cell, the UE is providedby higher layers with S≤10 search space sets where, for each searchspace set from the s search space sets, the UE is provided the followingby higher layer parameter SearchSpace:

-   -   a search space set index s, 0≤s<40, by higher layer parameter        searchSpaceId;    -   an association between the search space set s and a control        resource set p by higher layer parameter controlResourceSetId;    -   a PDCCH monitoring periodicity of k_(p,s) ⁻ candidates for DCI        format 2_0 and a corresponding CCE aggregation level;        -   an indication by higher layer parameter dci-Format2-1 to            monitor PDCCH candidates for DCI format 2_1;        -   an indication by higher layer parameter dci-Format2-2 to            monitor PDCCH candidates for DCI format 2_2;        -   an indication by higher layer parameter dci-Format2-3 to            monitor PDCCH candidates for DCI format 2_3;        -   if search space set s is a UE-specific search space set, an            indication by higher layer parameter dci-Formats to monitor            PDCCH candidate either for DCI format 0_0 and DCI format            1_0, or for DCI format 0_1 and DCI format 1_1.

If the higher layer parameter monitoringSymbolsWithinSlot indicates to aUE only one PDCCH monitoring occasion within a slot, the UE does notexpect to be configured with a PDCCH subcarrier spacing other than 15kHz for the corresponding search space set s if the control resource setp associated with the search space s includes at least one symbol afterthe third symbol of the slot.

A PDCCH UE-specific search space at CCE aggregation level L∈{1, 2, 4, 8,16} is defined by a set of PDCCH candidates for CCE aggregation level L.

If a UE is configured with higher layer parameterCrossCarrierSchedulingConfig for a serving cell the carrier indicatorfield value corresponds to the value indicated byCrossCarrierSchedulingConfig.

For a DL BWP of a serving cell on which a UE monitors PDCCH candidatesin a UE-specific search space, if the UE is not configured with acarrier indicator field, the UE monitors the PDCCH candidates withoutcarrier indicator field. For a serving cell on which a UE monitors PDCCHcandidates in a UE-specific search space, if a UE is configured with acarrier indicator field, the UE monitors the PDCCH candidates withcarrier indicator field.

A UE is not expected to monitor PDCCH candidates on a DL BWP of asecondary cell if the UE is configured to monitor PDCCH candidates withcarrier indicator field corresponding to that secondary cell in anotherserving cell. For the DL BWP of a serving cell on which the UE monitorsPDCCH candidates, the UE monitors PDCCH candidates at least for the sameserving cell.

11 UE-Group Common Signalling

11.1 Slot Configuration

A slot format includes downlink symbols, uplink symbols, and flexiblesymbols.

For each serving cell

If a UE is provided higher layer parameter tdd-UL-DL-ConfigurationCommonand the UE is not provided higher layer parametertdd-UL-DL-ConfigurationCommon2, the UE sets the slot format per slotover a number of slots as indicated by higher layer parametertdd-UL-DL-Configuration Common.

The higher layer parameter tdd-UL-DL-ConfigurationCommon provides

-   -   A reference subcarrier spacing μ_(ref) by higher layer parameter        referenceSubcarrierSpacing    -   A slot configuration period of P msec by higher layer parameter        dl-UL-TransmissionPeriodicity    -   A number of slots d_(slots) with only downlink symbols by higher        layer parameter nrofDownlinkSlots    -   A number of downlink symbols d_(sym) by higher layer parameter        nrofDownlinkSymbols    -   A number of slots u_(slots) with only uplink symbols by higher        layer parameter nrofUplinkSlots    -   A number of uplink symbols u_(sym) by higher layer parameter        nrofUplinkSymbols

A value P=0.625 msec is valid only for μ_(ref)=3. A value P=1.25 msec isvalid only for μ_(ref)=2 or μ_(ref)=3. A value P=2.5 msec is valid onlyfor μ_(ref)=1, or μ_(ref)=2, or μ_(ref)=3.

A slot configuration period of P msec includes S=P·2^(μ) ^(ref) slotswith μ_(ref) subcarrier spacing. From the S slots, a first d_(slots)slots include only downlink symbols and a last u_(slots) slots includeonly uplink symbols. The d_(sym) symbols after the first d_(slots) slotsare downlink symbols. The u_(sym) symbols before the last u_(slots)slots are uplink symbols. The remaining (S−d_(slots)−u_(slots))·N_(symb)^(slot)−d_(sym)−u_(sym) are flexible symbols.

The first symbol every 20/P periods is a first symbol in an even frame.

A UE expects that the reference subcarrier spacing μ_(ref) is smallerthan or equal to the subcarrier spacing for any of the configured DL BWPor UL BWP.

If the UE is provided higher layer parameterstdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationCommon2, the UEsets the slot format per slot over a first number of slots as indicatedby higher layer parameter tdd-UL-DL-ConfigurationCommon and the UE setsthe slot format per slot over a second number of slots as indicated bytdd-UL-DL-ConfigurationCommon2.

The higher layer parameter tdd-UL-DL-ConfigurationCommon2 provides

-   -   A reference subcarrier spacing μ_(ref,2) by higher layer        parameter referenceSubcarrierSpacing;    -   A slot configuration period of P₂ msec by higher layer parameter        dl-UL-TransmissionPeriodicity;    -   A number of slots d_(slots,2) with only downlink symbols by        higher layer parameter nrofDownlinkSlots;    -   A number of downlink symbols d_(sym,2) by higher layer parameter        nrofDownlinkSymbols;    -   A number of slots u_(slots,2) with only uplink symbols by higher        layer parameter nrofUplinkSlots;    -   A number of uplink symbols u_(sym,2) by higher layer parameter        nrofUplinkSymbols.

A UE expects μ_(ref2)=μ_(ref).

A value P₂=0.625 msec is valid only for μ_(ref,2)=3. A value P₂=1.25msec is valid only for μ_(ref,2)=2 or μ_(ref,2)=3. A value P₂=2.5 msecis valid only for μ_(ref,2)=2, or μ_(ref,2)=3.

A slot configuration period of P+P₂ slots includes first S=P·2^(μ)^(ref) slots and second S₂=P₂·2^(μ) ^(ref) slots. From the S₂ slots, afirst d_(slots,2) slots include only downlink symbols and a lastu_(slots,2) include only uplink symbols. The d_(sym,2) symbols after thefirst d_(slots,2) slots are downlink symbols. The u_(sym,2) symbolsbefore the last u_(slots,2) slots are uplink symbols. The remaining(S₂−d_(slot,2)−u_(slots,2))·N_(symb) ^(slot)−d_(sym,2)−u_(sym,2) areflexible symbols.

A UE expects that P+P₂ divides 20 msec.

The first symbol every 20/(P+P₂) periods is a first symbol in an evenframe.

If the UE is additionally provided higher layer parametertdd-UL-DL-ConfigDedicated, the parameter tdd-UL-DL-ConfigDedicatedoverrides only flexible symbols per slot over the number of slots asprovided by tdd-UL-DL-ConfigurationCommon ortdd-UL-DL-ConfigurationCommon2.

For each slot having a corresponding index provided by higher layerparameter slotIndex, the UE applies a format provided by thecorresponding higher layer parameter symbols. The UE does not expecttdd-UL-DL-ConfigDedicated to indicate as uplink or as downlink a symbolthat tdd-UL-DL-Configuration Common or, when provided,tdd-UL-DL-ConfigurationCommon2 indicates as a downlink or as an uplinksymbol, respectively.

For each slot configuration provided by tdd-UL-DL-ConfigDedicated, areference subcarrier spacing is the reference subcarrier spacing μ_(ref)provided by tdd-UL-DL-ConfigurationCommon.

A UE considers symbols in a slot indicated as downlink by higher layerparameters tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated to beavailable for receptions and considers symbols in a slot indicated asuplink by higher layer parameters tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, or by tdd-UL-DL-ConfigDedicated to beavailable for transmissions.

If a UE is not configured to monitor PDCCH for DCI format 2-0, for a setof symbols of a slot that are indicated as flexible by higher layerparameters tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to a UE, or when tdd-UL-DL-Configuration Common,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated are notprovided to the UE.

-   -   The UE receives PDSCH or CSI-RS in the set of symbols of the        slot if the UE receives a corresponding indication by a DCI        format 1_0, DCI format 1_1, or DCI format 0_1.    -   The UE transmits PUSCH, PUCCH, PRACH, or SRS in the set of        symbols of the slot if the UE receives a corresponding        indication by a DCI format 0_0, DCI format 0_1, DCI format 1_0,        DCI format 1_1, or DCI format 2_3.    -   If the UE is configured by higher layers to receive a PDCCH, or        a PDSCH, or a CSI-RS in the set of symbols of the slot, the UE        receives the PDCCH, the PDSCH, or the CSI-RS if        -   the UE does not detect a DCI format 0_0, DCI format 0_1, DCI            format 1_0, DCI format 1_1, or DCI format 2_3 that indicates            to the UE to transmit a PUSCH, a PUCCH, a PRACH, or a SRS in            the set of symbols of the slot, or        -   the UE detects a DCI format 0_0, DCI format 0_1, DCI format            1_0, DCI format 1_1, or DCI format 2_3 that indicates to the            UE to transmit a PUSCH, a PUCCH, a PRACH, or a SRS in the            set of symbols of the slot and a number of symbols between a            last symbol of a control resource set where the UE detects            the DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI            format 1_1, or DCI format 2_3 and a first symbol in the set            of symbols is smaller than the PUSCH preparation time N₂ for            the corresponding PUSCH timing capability [6, TS 38.214].

Otherwise, the UE does not receive the PDCCH, or the PDSCH, or theCSI-RS in the set of symbols of the slot.

-   -   If the UE is configured by higher layers to transmit a periodic        SRS, or a PUCCH, or a PUSCH, or a PRACH in the set of symbols in        the slot, the UE transmits the periodic SRS, or the PUCCH, or        the PUSCH, or the PRACH in the set of symbols of the slot if        -   the UE does not detect a DCI format 1_0, DCI format 1_1, or            DCI format 0_1 that indicates to the UE to receive PDSCH or            CSI-RS in the set of symbols in the slot, or        -   the UE detects a DCI format 1_0, DCI format 1_1, or DCI            format 0_1 that indicates to the UE to receive PDSCH or            CSI-RS in the set of symbols in the slot and a number of            symbols between a last symbol of a control resource set            where the UE detects the DCI format 1_0 or DCI format 1_1            and a first symbol in the set of symbols is smaller than the            PUSCH preparation time N₂ for the corresponding PUSCH timing            capability.

Otherwise, the UE does not transmit the periodic SRS, or the PUCCH, orthe PUSCH, or the PRACH in the set of symbols of the slot.

For a set of symbols of a slot that are indicated to a UE as uplink byhigher layer parameters tdd-UL-DL-Configuration Common,tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to the UE, the UE does not receive PDCCH, PDSCH, or CSI-RS inthe set of symbols of the slot.

For a set of symbols of a slot that are indicated to a UE as downlink byhigher layer parameters tdd-UL-DL-Configuration Common, ortdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to the UE, the UE does not transmit PUSCH, PUCCH, PRACH, or SRSin the set of symbols of the slot.

For a set of symbols of a slot that are indicated to a UE as flexible byhigher layer parameters tdd-UL-DL-Configuration Common, ortdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to the UE, the UE does not expect to receive both dedicatedhigher layer parameters configuring transmission from the UE in the setof symbols of the slot and dedicated higher layer parameters configuringreception by the UE in the set of symbols of the slot.

If a UE is scheduled by a DCI format 1_1 to receive PDSCH over multipleslots, and if higher layer parameters tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to the UE, indicate that, for a slot from the multiple slots,at least one symbol from a set of symbols where the UE is scheduledPDSCH reception in the slot is an uplink symbol, the UE does not receivethe PDSCH in the slot.

If a UE is scheduled by a DCI format 0_1 to transmit PUSCH over multipleslots, and if higher layer parameter tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-Configuration-Common2, or tdd-UL-DL-ConfigDedicated, whenprovided to a UE, indicates that, for a slot from the multiple slots, atleast one symbol from a set of symbols where the UE is scheduled PUSCHtransmission in the slot is a downlink symbol, the UE does not transmitthe PUSCH in the slot.

11.1.1 UE Procedure for Determining Slot Format

This subclause applies for a serving cell that is included in a set ofserving cells configured to a UE by higher layer parametersslotFormatCombToAddModList and slotFormatCombToReleaseList.

If a UE is configured by higher layers with parameterSlotFormatIndicator, the UE is provided with a SFI-RNTI by higher layerparameter sfi-RNTI and with a payload size of DCI format 2_0 by higherlayer parameter dci-PayloadSize. The UE is also provided in one or moreserving cells with a configuration for a search space set s and acorresponding control resource set p for monitoring M_(p,s) ^((L) ^(SFI)⁾ PDCCH candidates for DCI format 2_0 with a CCE aggregation level ofL_(SFI) CCEs as described in Subclause 10.1. The M_(p,s) ^((L) ^(SFI) ⁾PDCCH candidates are the first M_(p,s) ^((L) ^(SFI) ⁾ PDCCH candidatesfor CCE aggregation level L_(SFI) for search space set s in controlresource set p.

For each serving cell in the set of serving cells, the UE can beprovided:

-   -   an identity of the serving cell by higher layer parameter        servingCellId    -   a location of a SFI-index field in DCI format 2_0 by higher        layer parameter positionInDCI    -   a set of slot format combinations by higher layer parameter        slotFormatCombinations, where each slot format combination in        the set of slot format combinations includes        -   one or more slot formats indicated by a respective higher            layer parameter slotFormats for the slot format combination,            and        -   a mapping for the slot format combination provided by            slotFormats to a corresponding SFI-index field value in DCI            format 2_0 provided by higher layer parameter            slotFormatCombinationId    -   for unpaired spectrum operation, a reference subcarrier spacing        μ_(SFI) by higher layer parameter subcarrierSpacing and, when a        supplementary UL carrier is configured for the serving cell, a        reference subcarrier spacing μ_(SFI,SUL) by higher layer        parameter subcarrierSpacing2 for the supplementary UL carrier    -   for paired spectrum operation, a reference subcarrier spacing        μ_(SFI,DL) for a DL BWP by higher layer parameter        subcarrierSpacing and a reference subcarrier spacing μ_(SFI,UL)        for an UL BWP by higher layer parameter subcarrierSpacing2

A SFI-index field value in a DCI format 2_0 indicates to a UE a slotformat for each slot in a number of slots for each DL BWP or each UL BWPstarting from a slot where the UE detects the DCI format 2_0. The numberof slots is equal to or larger than a PDCCH monitoring periodicity forDCI format 2_0. The SFI-index field includes log₂ (maxSFIindex) bitswhere maxSFIindex is the maximum value of the values provided bycorresponding higher layer parameters slotFormatCombinationId. A slotformat is identified by a corresponding format index as provided inTable 11.1.1-1 where ‘D’ denotes a downlink symbol, ‘U’ denotes anuplink symbol, and ‘F’ denotes a flexible symbol.

If a PDCCH monitoring periodicity for DCI format 2_0, provided to a UEfor the search space set s by higher layer parametermonitoringSlotPeriodicityAndOffset, is smaller than a duration of a slotformat combination the UE obtains at a PDCCH monitoring occasion for DCIformat 2_0 by a corresponding SFI-index field value, and the UE detectsmore than one DCI formats 2_0 indicating a slot format for a slot, theUE expects each of the more than one DCI formats 2_0 to indicate a sameformat for the slot.

[Table 11.1.1-1 of 3GPP TS 38.213 V15.2.0, entitled “Slot formats fornormal cyclic prefix”, is reproduced as FIGS. 5A and 5B]

For unpaired spectrum operation for a UE on a serving cell, the UE isprovided by higher layer parameter subcarrierSpacing a referencesubcarrier spacing configuration of μ_(SFI) for each slot format in acombination of slot formats indicated by a SFI-index field value in DCIformat 2_0. The UE expects that for a reference subcarrier spacingconfiguration of μ_(SFI) and for an active DL BWP and UL BWP pair withsubcarrier spacing configuration of u, it is μ≥μ_(SFI). Each slot formatin the combination of slot formats indicated by the SFI-index fieldvalue in DCI format 2_0 is applicable to 2^((μ-μ) ^(SFI) ⁾ consecutiveslots in the active DL BWP and UL BWP pair where the first slot startsat a same time as a first slot for the reference subcarrier spacingconfiguration of μ_(SFI) and each downlink or flexible or uplink symbolfor the reference subcarrier spacing configuration of μ_(SFI)corresponds to 2^((μ-μ) ^(SFI) ⁾ consecutive downlink or flexible oruplink symbols for the subcarrier spacing configuration u.

A reference subcarrier spacing configurations of μ_(SFI), or μ_(SFI,DL),or μ_(SFI,SUL) is either 0, or 1, or 2 for frequency range 1 and iseither 2 or 3 for frequency range 2.

For a set of symbols of a slot, a UE does not expect to detect a DCIformat 2_0 with an SFI-index field value indicating the set of symbolsof the slot as uplink and to detect a DCI format 1_0, a DCI format 1_1,or DCI format 0_1 indicating to the UE to receive PDSCH or CSI-RS in theset of symbols of the slot.

For a set of symbols of a slot, a UE does not expect to detect a DCIformat 2_0 with an SFI-index field value indicating the set of symbolsin the slot as downlink and to detect a DCI format 0_0, DCI format 0_1,DCI format 1_0, DCI format 1_1, or DCI format 2_3 indicating to the UEto transmit PUSCH, PUCCH, PRACH, or SRS in the set of symbols of theslot.

For a set of symbols of a slot that are indicated as downlink/uplink byhigher layer parameters tdd-UL-DL-Configuration Common,tdd-UL-DL-ConfigurationCommon2, or tdd-UL-DL-ConfigDedicated, whenprovided to a UE, the UE does not expect to detect a DCI format 2_0 withan SFI-index field value indicating the set of

For a set of symbols of a slot indicated to a UE as flexible by higherlayer parameters tdd-UL-DL-Configuration Common,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated, whenprovided to the UE, or when higher layer parameterstdd-UL-DL-ConfigurationCommon, tdd-UL-DL-ConfigurationCommon2, andtdd-UL-DL-ConfigDedicated are not provided to the UE, and if the UEdetects a DCI format 2_0 providing a format for the slot using a slotformat value other than 255

-   -   If one or more symbols from the set of symbols are symbols in a        control resource set configured to the UE for PDCCH monitoring,        the UE receives PDCCH in the control resource set only if an        SFI-index field value in DCI format 2_0 indicates that the one        or more symbols are downlink symbols.    -   If an SFI-index field value in DCI format 2_0 indicates the set        of symbols of the slot as flexible and the UE detects a DCI        format 1_0, DCI format 1_1, or DCI format 0_1 indicating to the        UE to receive PDSCH or CSI-RS in the set of symbols of the slot,        the UE receives PDSCH or CSI-RS in the set of symbols of the        slot.    -   If an SFI-index field value in DCI format 2_0 indicates the set        of symbols of the slot as flexible and the UE detects a DCI        format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or        DCI format 2_3 indicating to the UE to transmit PUSCH, PUCCH,        PRACH, or SRS in the set of symbols of the slot the UE transmits        the PUSCH, PUCCH, PRACH, or SRS in the set of symbols of the        slot.    -   If an SFI-index field value in DCI format 2_0 indicates the set        of symbols of the slot as flexible, and the UE does not detect a        DCI format 1_0, DCI format 1_1, or DCI format 0_1 indicating to        the UE to receive PDSCH or CSI-RS, or the UE does not detect a        DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1,        or DCI format 2_3 indicating to the UE to transmit PUSCH, PUCCH,        PRACH, or SRS in the set of symbols of the slot, the UE does not        transmit or receive in the set of symbols of the slot.    -   If the UE is configured by higher layers to receive PDSCH or        CSI-RS in the set of symbols of the slot, the UE receives the        PDSCH or the CSI-RS in the set of symbols of the slot only if an        SFI-index field value in DCI format 2_0 indicates the set of        symbols of the slot as downlink.    -   If the UE is configured by higher layers to transmit PUCCH, or        PUSCH, or PRACH in the set of symbols of the slot, the UE        transmits the PUCCH, or the PUSCH, or the PRACH in the slot only        if an SFI-index field value in DCI format 2_0 indicates the set        of symbols of the slot as uplink.    -   If the UE is configured by higher layers to transmit periodic        SRS in the set of symbols of the slot, the UE transmits the        periodic SRS only in a subset of symbols from the set of symbols        of the slot indicated as uplink symbols by an SFI-index field        value in DCI format 2_0.    -   A UE does not expect to detect an SFI-index field value in DCI        format 2_0 indicating the set of symbols of the slot as downlink        and also detect a DCI format 0_0, DCI format 0_1, DCI format        1_0, DCI format 1_1, or DCI format 2_3 indicating to the UE to        transmit SRS, PUSCH, PUCCH, or PRACH, in one or more symbols        from the set of symbols of the slot.    -   A UE does not expect to detect an SFI-index field value in DCI        format 2_0 indicating the set of symbols of the slot as downlink        if the set of symbols of the slot includes symbols corresponding        to a first repetition of a PUSCH transmission activated by an UL        Type 2 grant PDCCH as described in Subclause 10.2.    -   A UE does not expect to detect an SFI-index field value in DCI        format 2_0 indicating the set of symbols of the slot as uplink        and also detect a DCI format 1_0 or DCI format 1_1 or DCI format        0_1 indicating to the UE to receive PDSCH or CSI-RS in one or        more symbols from the set of symbols of the slot.

If a UE is configured by higher layers to receive a CSI-RS or a PDSCH ina set of symbols of a slot and the UE detects a DCI format 20 with aslot format value other than 255 that indicates a slot format with asubset of symbols from the set of symbols as uplink or flexible, or theUE detects a DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format1_1, or DCI format 2_3 indicating to the UE to transmit PUSCH, PUCCH,SRS, or PRACH in at least one symbol in the set of the symbols, the UEcancels the CSI-RS reception in the set of symbols of the slot orcancels the PDSCH reception in the slot.

A UE assumes that flexible symbols in a control resource set configuredto the UE for PDCCH monitoring are downlink symbols if the UE does notdetect an SFI-index field value in DCI format 2_0 indicating the set ofsymbols of the slot as flexible or uplink and the UE does not detect aDCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or DCIformat 2_3 indicating to the UE to transmit SRS, PUSCH, PUCCH, or PRACHin the set of symbols.

For a set of symbols of a slot that are indicated as flexible by higherlayer parameters tdd-UL-DL-Configuration Common,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated, whenprovided to a UE, or when higher layer parameterstdd-UL-DL-ConfigurationCommon, or tdd-UL-DL-ConfigurationCommon2, andtdd-UL-DL-ConfigDedicated are not provided to the UE, and if the UE doesnot detect a DCI format 2_0 providing a slot format for the slot.

-   -   The UE receives PDSCH or CSI-RS in the set of symbols of the        slot if the UE receives a corresponding indication by a DCI        format 1_0, DCI format 1_1, or DCI format 0_1.    -   The UE transmits PUSCH, PUCCH, PRACH, or SRS in the set of        symbols of the slot if the UE receives a corresponding        indication by a DCI format 0_0, DCI format 0_1, DCI format 1_0,        DCI format 1_1, or DCI format 2_3.    -   The UE receives PDCCH as described in Subclause 11.1.    -   If the UE is configured by higher layers to receive PDSCH or        CSI-RS in the set of symbols of the slot, the UE does not        receive the PDSCH or the CSI-RS in the set of symbols of the        slot.    -   If the UE is configured by higher layers to transmit periodic        SRS, or PUCCH, or PUSCH, or PRACH in the set of symbols of the        slot, the UE        -   does not transmit the PUCCH, or the PUSCH, or the PRACH in            the slot and does not transmit the SRS in symbols from the            set of symbols in the slot, if any, starting from a symbol            that is a number of symbols equal to the PUSCH preparation            time N₂ for the corresponding PUSCH timing capability after            a last symbol of a control resource set where the UE is            configured to monitor PDCCH for DCI format 2_0;        -   is not expected to cancel the transmission of the periodic            SRS, or the PUCCH, or the PUSCH, or the PRACH in symbols            from the set of symbols in the slot, if any, starting before            a symbol that is a number of symbols equal to the PUSCH            preparation time N₂ for the corresponding PUSCH timing            capability after a last symbol of a control resource set            where the UE is configured to monitor PDCCH for DCI format            2_0.

The Final Report of 3GPP TSG RAN WG1 #AH_1801 v1.0.0 includes thefollowing agreements:

Agreements:

-   -   Explicitly add reference SCS field in UE-specific SFI table        configuration        -   The UE does not expect the reference SCS to have larger SCS            than any of the configured BWP the GC-PDCCH is configured            for        -   The reference SCS is UE-specifically configured per cell            (new RRC parameter)            -   For FR1: 15 kHz/30 kHz/60 kHz            -   For FR2: 60 kHz/120 kHz

Agreement:

-   -   UE-specific SFI table configuration (including reference SCS(s))        is per cell

The Final Report of 3GPP TSG RAN WG1 #92 v1.0.0 includes the followingagreements related to frame structure and/or SFI (Slot FormatIndication):

Agreement:

-   -   For the CSS which a DCI format 2_0 is configured to be monitored        on, the UE will only monitor the first one or two (from SFI        configuration) PDCCH candidates of the configured aggregation        level for DCI format 2_0

Agreement:

-   -   If a configured DCI format 2_0 is not received, PDCCH monitoring        is performed till the next configured DCI format 2_0 monitoring        occasion

Agreement:

-   -   Restrict the combined periodicity for cell-specific DL/UL        assignment to such that 20 ms is a multiple of the combined        periodicity

Agreement:

-   -   When the cell-specific DL/UL configuration is configured, no        explicit offset is provided for the starting slot of the        configured period, but the first slot of each even radio frame        should be a starting slot of the configured cell-specific DL/UL        pattern

Agreement:

-   -   If a configured DCI format 2_0 is not received, before the next        configured DCI format 2_0 monitoring occasion, UE will cancel        RRC configured transmission, and assume RRC configured DL        transmission is not transmitted, during semi-static configured        flexible symbols

Agreement:

Study the additional functionality needed beyond the specifications foroperation in licensed spectrum in the following deployment scenarios.

-   -   Carrier aggregation between licensed band NR (PCell) and NR-U        (SCell)        -   NR-U SCell may have both DL and UL, or DL-only.    -   Dual connectivity between licensed band LTE (PCell) and NR-U        (PSCell)    -   Stand-alone NR-U    -   An NR cell with DL in unlicensed band and UL in licensed band    -   Dual connectivity between licensed band NR (PCell) and NR-U        (PSCell)

The Final Report of 3GPP TSG RAN WG1 #92bis v1.0.0 includes thefollowing agreements related to frame structure and/or SFI (Slot FormatIndication):

Agreements:

-   -   UE does not expect the reference SCS in TDD UL/DL configuration        common and common2 to be different    -   UE does not expect the reference SCS in cell-specific UL/DL        configuration in a cell to be larger than the SCS of any BWP        configured for the cell

Agreement:

-   -   Limit the size of the UE-specific SFI table to a max total of        512 values across all entries in Rel 15.

Agreement:

-   -   UE is not expected to monitor GC-PDCCH for SFI for a first cell        in another cell with larger SCS than the first cell in Rel-15.

Agreement

-   -   In the slot format table in TS38.211, the entry 255 is defined        such that when a slot format for a slot is indicated as 255, the        UE does not use this information in deciding the cancellation of        UE-specific RRC configured DL receptions or UE-specific RRC        configured UL transmissions

Agreements:

-   -   For a grant based PDSCH, rate matching around RRC configured        CSI-RS, if the CSI-RS is cancelled by setting SFI to “flexible”        or the UE does not detect the SFI for the slot, the PDSCH still        rate match around the CSI-RS RE locations.        -   This may not have spec impact

The Draft Report of 3GPP TSG RAN WG1 #93 v0.2.0 includes the followingagreements related to frame structure and/or SFI (Slot FormatIndication):

Agreements:

-   -   When a configured SFI monitoring is cancelled under the        condition that the symbols are indicated to be UL or flexible by        an earlier SFI        -   (Follow earlier agreement on configure DCI format 2_0 not            detected) For the slots till the next configured DCI format            2_0 monitoring occasion with slot format not provided by            earlier SFI, PDCCH monitoring is performed but the UE will            cancel RRC configured transmission, and assume RRC            configured DL transmission is not transmitted, during            semi-static configured flexible symbols            -   Spec change may not be needed    -   If GC-PDCCH monitoring is skipped due to DRX (treat this the        same as if the configured GC-PDCCH monitoring is not detected)        -   (Follow earlier agreement on configure DCI format 2_0 not            detected) For the slots in the DRX ON cycle before the next            configured DCI format 2_0 monitoring occasion, PDCCH            monitoring is performed but the UE will cancel RRC            configured transmission, and assume RRC configured DL            transmission is not transmitted, during semi-static            configured flexible symbols            -   Spec change may not be needed

Agreement:

-   -   When configure the UE-specific SFI table, each entry at least        explicitly specifies the slot formats for the slots equals to        the configured SFI monitoring periodicity.

Agreement:

-   -   For Rel.15, on semi-static flexible symbol in a TDD cell, UE        does not expect simultaneous RRC configurated DL reception and        RRC configured UL transmission in the same symbol.

Conclusion:

-   -   For the previous agreement “For a slot covered by multiple SFIs        transmitted at different slots, the UE does not expect to        receive different slot format indicated by different SFIs”, this        include the case 255 is used for the slot format as well.

Agreement:

-   -   For the previous agreement on “RRC configured DL reception and        RRC configured UL transmission cancellation based on        miss-detection of configured DCI format 2_0 monitoring” only        applies for slots when their slot formats are not indicated by        any other detected DCI format 2_0.

R1-1806105 provides the following description:

3. Frame Structure

3.1 COT Structure

In a licensed band (esp. latency critical) scenario, the deployment offrequent DL-UL and UL-DL switching points is well motivated. On theother hand, when operating in unlicensed band scenario, because of theregulations, it may sometimes make sense to operate with less frequentswitching points to match the regulatory requirements w.r.t. MaximumChannel Occupancy Time (MCOT) at the cost of latency, of course.

It was agreed in RAN1 #92bis to “study supporting more than oneswitching points within a TxOP”. FIG. 1 shows an example with TxOP withone and two switching points. Support for multiple switching points canprovide e.g. improved latency performance without increasing theoverhead of frequent (Type 1) channel access procedures too much. FromHARQ/scheduling point of view, it is not a problem to support TxOP withmultiple switching points: Similar functionality is supported alreadyfor NR licensed band operation.

Multiple switching points within a TxOP needs to be taken into accountin the channel access procedures. The length of the switching gapbetween different link directions needs to be considered as well. Oneexample of multiple switching points within a TxOP is shown in FIG. 1 :

-   -   gNB performs Type 1 LBT at the beginning of TxOP (similarly as        in LTE LAA)    -   UEs perform Type 2 LBT at the beginning of the first UL portion        (similarly as in LTE LAA)    -   In the case of two switching points, gNB/UE perform Type 2 LBT        or no LBT before the 2^(nd) transmission.

Observation 1: Introduction of multiple-switching points within COT doesnot necessarily increase the frequency of TYPE 2 LBT, whilesignificantly reduces the latency.

[FIG. 1 of 3GPP R1-1806105, entitled “TxOP with 1 and 2 switchingpoints”, is reproduced as FIG. 6 ]

NR operation should support wide range of UL/DL ratios, including oneswhere there are several consecutive DL or UL slots. Hence, there is aneed for fully flexible operation in terms of DL/UL switching, which canbe achieved by means of the three basic slot types: bi-directional slot,DL-only slot and UL-only slot. It was agreed in RAN1 #92bis that “NR-Usupports both Type-A and Type-B mapping”. Type-B mapping (a.k.a.non-slot based scheduling with DMRS in the first symbols of PxSCH)allows flexible starting position in a slot and can reduce the timebetween the possible consecutive transmission starting positions. Type-Amapping, unlike TYPE-B, supports more flexible PDSCH/PUSCH time-domainresource allocations. Hence it can provide flexible ending symbol forthe TxOP.

Generally speaking, NR frame structure defined for licensed spectrumscenarios provides a very good baseline from NR-U point of view, andonly minor changes to the slot formats compared to licensed bandoperation are foreseen. For example, NR-U should introduce a possibilityto have short PUCCH at the beginning of UL portion of the COT in thecase of UL-only or bi-directional UL slots.

Proposal 6: NR Unlicensed band operation can be based on fixed frametiming and slot formats defined in NR Rel-15.

Proposal 7: NR-U operation should support short PUCCH located at thebeginning of the UL portion of the COT.

Proposal 8: Study LBT options for the case with multiple switchingpoints within a TxOP.

3.2 Mini-Slot Based Operation

When NR is applied on unlicensed bands requiring contention basedchannel access procedure, it is beneficial that gNB or UE can swiftlyoccupy channel once the channel access procedure indicates the channelto be vacant. If gNB or UE waits for too long in self-deferral to aligntransmissions with slot boundary, more agile systems may occupy thechannel in the meanwhile.

It was agreed in RAN1 #92bis that “NR-U supports both Type-A and Type-Bmapping, and “Additional starting positions and durations are notprecluded”. Mini-slots represent an efficient way to reduce the timebetween the possible consecutive transmission starting positions.However, more frequent transmission starting positions increase DLcontrol channel blind decoding burden on the UE side and a reasonabletrade-off between the DL control channel decoding burden and frequencyof transmission starting positions is needed. FIG. 2 illustrates oneexample:

-   -   UE is configured with PDCCH monitoring periodicity of 2 OFDM        symbols    -   The first mini-slots are used for aligning the ending position        of the first transmission(s) with the slot boundary    -   After the first mini-slots the UE continues PDCCH monitoring        using periodicity of one slot.

This approach has several benefits:

-   -   UE power saving: unnecessary PDCCH monitoring with a high        periodicity (such as 2 OFDM symbols) can be avoided within the        COT    -   Reduced control channel and DMRS overhead (unnecessary mini-slot        based PDCCH, HARQ-ACK and DMRS overhead is avoided) without        compromising fast channel access.    -   This approach can facilitate also smooth implementation as gNB        can prepare DL transmission in advance w/o knowing the absolute        starting timing of the starting time.

Proposal 9: Consider PDCCH monitoring, where non-slot based monitoringis used at the beginning of the COT and slot-based monitoring is usedafter first mini-slot(s) of the COT

[FIG. 2 of 3GPP R1-1806105, entitled “PDCCH monitoring”, is reproducedas FIG. 7 ]

When gNB is contending for channel access on unlicensed band, gNB needsto have a mini-slot or a slot ready for transmission, but it does notknow when it can access channel and transmit the preparedmini-slot/slot. If mini-slot structure (including PDCCH) depends on thetime, e.g. in terms of scrambling or pilot positions/sequence, gNB needsto repeatedly re-build mini-slots with the same data while it iscontending for channel access. A simpler implementation is achieved ifgNB can build a mini-slot only once and then wait for channel access.This is possible if mini-slot structure/signal does not depend on time.Of course, this presents challenges for multiplexing of periodic signalsto mini-slots, which requires further studies. Also, uncompromisedinter-cell interference randomization via scrambling may be needed insome scenarios, implying that the time dependency/independency ofmini-slot structure could be a configurable option or would only beapplied for the mini-slots at the beginning of the COT.

Proposal 10: Possibilities for (mini-)slot structure independent fromtime are investigated.

Detecting the DL Transmission:

In LTE, there are CRS (cell-specific reference signals) present in eachDL subframe and they can be used also for detecting the DL transmissionin different LTE LAA scenarios. The CRS based approach cannot be usedfor NR-U simply because there are no CRS in the NR.

There are different options for detecting the DL transmission in NR-U:

-   -   PDCCH monitoring: it can be assumed that monitoring on the full        search space/number BDs is not possible at least in the cases        when there are multiple starting positions/slot defined.    -   PDCCH DMRS-based detection. This requires that PDCCH DMRS is        transmitted via the entire CORESET at least in the beginning of        the DL transmission.    -   Detection of preamble at the beginning of DL transmission.        Preamble can be constructed e.g. from CSI-RS/TRS and/or PSS/SSS.

We think that these options should be studied as part of the NR-U studyitem.

Proposal 11: Study different options to detect DL transmission in NR-U

3.3 Indicating the COT Structure

NR licensed band operation supports both semi-static and dynamicconfiguration for SFI. We think that these options need to be supportedalso for NR-U:

-   -   Semi-statically configured resources can be used e.g. for        discovery reference signal and PRACH resources    -   Dynamic indication of the time-varying COT structure is conveyed        using GC-PDCCH.

Dynamic indication of the COT structure provides many benefits includingthe following:

-   -   It enables usage of Type 2 LBT at the UE.    -   GC-PDCCH can be used to determine the location of the short        PUCCH at the beginning of UL portion of the COT.    -   Provides opportunities for UE power saving (e.g. no PDCCH        monitoring during UL portion of the COT)    -   It can be used to aid CSI measurement at the UE.    -   It can be used to detect (and/or validate) DL transmission        detection.

It makes sense to use GC-PDCCH for SFI defined in NR-Rel-15 as thestarting point also for NR-U studies. However, NR-U specific aspectsneed to be considered as well. Those include e.g. NR-U-specific slotformats, wideband operation (based on 20 MHz sub-band), and support formultiple switching points within a COT.

Proposal 12: Use NR-U specific GC-PDCCH for dynamic indication of theCOT structure.

-   -   GC-PDCCH for SFI defined in NR-Rel-15 can be used as the        starting point for discussion

3GPP TS 38.212 describes a DCI (Downlink Control Information) format forindicating slot format as follows:

7.3.1 DCI Formats

The DCI formats defined in table 7.3.1-1 are supported.

[Table 7.3.1-1 of 3GPP TS 38.212 v15.2.0, entitled “DCI formats”, isreproduced as FIG. 8 ]

The fields defined in the DCI formats below are mapped to theinformation bits a₀ to a_(A-1) as follows.

Each field is mapped in the order in which it appears in thedescription, including the zero-padding bit(s), if any, with the firstfield mapped to the lowest order information bit a₀ and each successivefield mapped to higher order information bits. The most significant bitof each field is mapped to the lowest order information bit for thatfield, e.g. the most significant bit of the first field is mapped to a₀.

If the number of information bits in a DCI format is less than 12 bits,zeros shall be appended to the DCI format until the payload size equals12.

7.3.1.3.1 Format 2_0

DCI format 2_0 is used for notifying the slot format.

The following information is transmitted by means of the DCI format 2_0with CRC scrambled by SFI-RNTI:

-   -   Slot format indicator 1, Slot format indicator 2, . . . , Slot        format indicator N.

The size of DCI format 2_0 is configurable by higher layers up to 128bits, according to Subclause 11.1.1 of [5, TS 38.213].

3GPP TS 36.213 describes channel access procedures in LTE LAA/eLAA/FeLAAas follows:

15 Channel Access Procedures for LAA

15.1 Downlink Channel Access Procedures

An eNB operating LAA Scell(s) shall perform the channel accessprocedures described in this sub clause for accessing the channel(s) onwhich the LAA Scell(s) transmission(s) are performed.

15.1.1 Channel Access Procedure for Transmission(s) IncludingPDSCH/PDCCH/EPDCCH

The eNB may transmit a transmission including PDSCH/PDCCH/EPDCCH on acarrier on which LAA Scell(s) transmission(s) are performed, after firstsensing the channel to be idle during the slot durations of a deferduration T_(d); and after the counter N is zero in step 4. The counter Nis adjusted by sensing the channel for additional slot duration(s)according to the steps below:

-   -   1) set N=N_(init), where N_(init) is a random number uniformly        distributed between 0 and CW_(p), and go to step 4;    -   2) if N>0 and the eNB chooses to decrement the counter, set        N=N−1;    -   3) sense the channel for an additional slot duration, and if the        additional slot duration is idle, go to step 4; else, go to step        5;    -   4) if N=0, stop; else, go to step 2.    -   5) sense the channel until either a busy slot is detected within        an additional defer duration T_(d) or all the slots of the        additional defer duration T_(d) are detected to be idle;    -   6) if the channel is sensed to be idle during all the slot        durations of the additional defer duration T_(d), go to step 4;        else, go to step 5;

If an eNB has not transmitted a transmission includingPDSCH/PDCCH/EPDCCH on a carrier on which LAA Scell(s) transmission(s)are performed after step 4 in the procedure above, the eNB may transmita transmission including PDSCH/PDCCH/EPDCCH on the carrier, if thechannel is sensed to be idle at least in a slot duration T_(sl) when theeNB is ready to transmit PDSCH/PDCCH/EPDCCH and if the channel has beensensed to be idle during all the slot durations of a defer durationT_(d) immediately before this transmission. If the channel has not beensensed to be idle in a slot duration T_(sl) when the eNB first sensesthe channel after it is ready to transmit or if the channel has beensensed to be not idle during any of the slot durations of a deferduration T_(d) immediately before this intended transmission, the eNBproceeds to step 1 after sensing the channel to be idle during the slotdurations of a defer duration T_(d).

The defer duration T_(d) consists of duration T_(f)=16 us immediatelyfollowed by m_(p) consecutive slot durations where each slot duration isT_(sl)=9 us, and T_(f) includes an idle slot duration T_(sl) at start ofT_(f);

A slot duration T_(sl) is considered to be idle if the eNB senses thechannel during the slot duration, and the power detected by the eNB forat least 4 us within the slot duration is less than energy detectionthreshold X_(Thresh). Otherwise, the slot duration T_(sl) is consideredto be busy.

CW_(min,p)≤CW_(p)≤CW_(max,p) is the contention window. CW_(p) adjustmentis described in sub clause 15.1.3.

CW_(min,p) and CW_(max,p) are chosen before step 1 of the procedureabove.

m_(p), CW_(min,p), and CW_(max,p) are based on channel access priorityclass associated with the eNB transmission, as shown in Table 15.1.1-1.

X_(Thresh) adjustment is described in sub clause 15.1.4

If the eNB transmits discovery signal transmission(s) not includingPDSCH/PDCCH/EPDCCH when N>0 in the procedure above, the eNB shall notdecrement N during the slot duration(s) overlapping with discoverysignal transmission.

The eNB shall not continuously transmit on a carrier on which the LAAScell(s) transmission(s) are performed, for a period exceedingT_(mcot,p) as given in Table 15.1.1-1.

For p=3 and p=4, if the absence of any other technology sharing thecarrier can be guaranteed on a long term basis (e.g. by level ofregulation), T_(mcot,p)=10 ms, otherwise, T_(mcot,p)=8 ms.

[Table 15.1.1-1 of 3GPP TS 36.213 v15.1.0, entitled “Channel AccessPriority Class”, is reproduced as FIG. 9 ]

For LAA operation in Japan, if the eNB has transmitted a transmissionafter N=0 in step 4 of the procedure above, the eNB may transmit thenext continuous transmission, for duration of maximum T=4 msec,immediately after sensing the channel to be idle for at least a sensinginterval of T_(js)=34 usec and if the total sensing and transmissiontime is not more than 1000·T_(mcot)+┌T_(mcot)/T_(j)−1┐·T_(js) μsec.T_(js) consists of duration T_(f)=16 us immediately followed by two slotdurations T_(sl)=9 us each and T_(f) includes an idle slot durationT_(sl) at start of T_(f). The channel is considered to be idle forT_(js) if it is sensed to be idle during the during the slot durationsof T_(js).

One or multiple of following terminologies may be used hereafter:

-   -   BS: A network central unit or a network node in NR which is used        to control one or multiple TRPs which are associated with one or        multiple cells. Communication between BS and TRP(s) is via        fronthaul. BS could also be referred to as central unit (CU),        eNB, gNB, or NodeB.    -   TRP: A transmission and reception point provides network        coverage and directly communicates with UEs. TRP could also be        referred to as distributed unit (DU) or network node.    -   Cell: A cell is composed of one or multiple associated TRPs,        i.e. coverage of the cell is composed of coverage of all        associated TRP(s). One cell is controlled by one BS. Cell could        also be referred to as TRP group (TRPG).    -   Serving beam: A serving beam for a UE is a beam generated by a        network node, e.g. TRP, which is currently used to communicate        with the UE, e.g. for transmission and/or reception.    -   Candidate beam: A candidate beam for a UE is a candidate of a        serving beam. Serving beam may or may not be candidate beam.

In LTE LAA/eLAA/FeLAA, before initiating a transmission, a wireless nodeshall perform a channel access procedure and/or LBT (Listen Before Talk)scheme successfully. As discussed in 3GPP TS 36.213, after a successfulchannel access procedure and/or LBT scheme, the wireless node is allowedto transmit for a period of time based on the traffic type with amaximum length limit called maximum channel occupancy time (MCOT). Thetime period in which the wireless node actually transmits could be aportion of the MCOT, and is called channel occupancy time (COT). Withinthe channel occupancy time, the wireless node, could performtransmission similar to licensed band.

In NR licensed band operation, network could indicate slot format orframe structure by semi-static signaling and/or dynamic signaling.Moreover, dynamic signaling could be a group common signaling and/or anunicast signaling. In 3GPP TS 38.213, a group common signaling could bedownlink control information (DCI) format 2_0. For NR-U, it is good toinherit NR's signaling for indicating slot format. However, due touncertainty of timing of a successful channel access procedure or LBTscheme performed by a UE or network, it is less beneficial to indicateslot format or frame structure by semi-static signaling. Instead, UEcould be indicated slot format of unlicensed spectrum or cell based ondynamic signaling (e.g. downlink control information or group commonDCI).

The study item of NR-based access to unlicensed spectrum (NR-U) wasapproved in RAN #75 meeting. The flexible design in NR, semi-staticsignaling, and/or dynamic signaling could indicate slot format in NR-U.Both semi-static signaling and/or dynamic signaling need to beconfigured in advance. Even though it is the dynamic signaling, gNBneeds to configure periodic monitoring occasion for UE to receive thedynamic signaling. However, due to uncertainty of LBT, one or more thanone monitoring occasion may occur outside COT of network node or basestation (e.g. gNB). Based on the NR PHY standard (as discussed in 3GPPTS 38.213), the UE may apply procedure related to SFI miss (e.g.procedure or behavior in response to not detecting a SFI on configuredoccasions) if UE does not receive SFI. For a set of OFDM (OrthogonalFrequency Division Multiplexing) symbol indicated by semi-staticsignaling (i.e. RRC signaling) as “flexible” before next SFI monitoringoccasion, the UE does not perform configured transmission or reception,perform periodic measurement except for performing control resource set(CORESET) monitoring on the set of OFDM symbol.

If the set of OFDM symbol is outside gNB's COT, it is quite reasonablefor UE to only perform CORESET monitoring. However, if the set of OFDMsymbol occurs in gNB's COT while SFI monitoring occasion is outsidegNB's COT, it may be too conservative for UE to only perform CORESETmonitoring. Since when gNB occupied the channel, gNB and UE may performmeasurement for avoiding hidden node's problem. If periodic measurementis canceled due to SFI monitoring occasion outside gNB's COT, gNB mayneed to transmit a UE-specific DCI for triggering measurement. It mayincur unnecessary signaling overhead. Possible solutions for the issueare described below.

One general concept is that UE could assume or determine slot format ofslots during a set of OFDM symbols is determined based on RRCsignaling(s). A set of OFDM symbols could be starting from beginning ofthe OFDM symbol where the UE detects a channel indicator and/or detectsor be indicated a channel occupation until beginning of the first OFDMsymbol of a SFI monitoring occasion. If UE is configured to performtransmission and/or reception within the set of OFDM symbols, the UEcould perform the configured transmission and/or reception. The channelindicator could indicate (starting position of) a network's channeloccupancy time (COT). In one embodiment, the SFI monitoring occasioncould be a next or the nearest SFI monitoring occasion after the UEdetects the channel indicator and/or detects or be indicated a channeloccupation.

Another general concept is that a network could transmit a channelindicator to indicate or trigger UE to perform configured transmissionand/or reception on a set of OFDM symbols, wherein the set of OFDMsymbols are starting from the OFDM symbol where the network transmitsthe channel indicator and ending before a SFI monitoring occasion. Inone embodiment, the SFI monitoring occasion could be a next or thenearest SFI monitoring occasion after the network's COT starts or afterthe network starts transmits a physical channel or RS receivable forserved UE(s).

Another general concept is that a network transmits a slot formatindication (SFI) for an unlicensed serving cell on starting slot orstarting OFDM symbol of the network's COT in the unlicensed servingcell. In one embodiment, a slot format indication (SFI) could be a slotformat indicator. In one embodiment, the SFI is transmitted on (orimmediately after) a first allowable transmission boundary fortransmitting a physical channel and/or RS within the network's COT inthe unlicensed serving cell, wherein the transmitted physical channeland/or RS is receivable or decodable for served UE(s).

Another general concept is that slot format of slots outside a network'sCOT is assumed or considered by a UE as that each symbol in those slotsis flexible. In one embodiment, slot format of slots inside thenetwork's COT could be assumed or considered by the UE as that eachsymbol in those slots is flexible. Furthermore, slot format of slotsinside the network's COT could be indicated by network, e.g. an SFI.

Any concepts discussed above can be formed or combined to form anembodiment. Some or all concepts discussed above can be combined to forman embodiment. In one embodiment, a set of OFDM symbols could compriseconsecutive OFDM symbols. In one embodiment, a set of OFDM symbols couldcomprise consecutive OFDM symbols with one or more gap embedded inbetween.

Embodiment 1—A UE could be configured to transmit and/or receive in anunlicensed serving cell. The UE could be configured to performtransmission or reception on a (pre-)configured resource. In oneembodiment, the UE could be configured to perform transmission orreception on a (pre-)configured resource (within a COT) (of network).More specifically, the UE could be configured to perform transmission orreception on a (pre-)configured resource (within a COT) in theunlicensed serving cell.

If the (pre-)configured resource is within a set of OFDM symbols, the UEcould perform the transmission or reception on the (pre-)configuredresource. In one embodiment, if the (pre-)configured resource is withina set of OFDM symbols and if a most recent SFI monitoring occasionbefore the set of OFDM symbols is outside the COT, or if the(pre-)configured resource is within a set of OFDM symbols and if a mostrecent SFI monitoring occasion before the set of OFDM symbols is locatedbefore the UE detects a channel indicator, the UE could perform thetransmission or reception on the (pre-)configured resource even if theUE does not detect and/or receive an SFI (for the unlicensed servingcell) on the most recent SFI monitoring occasion.

In one embodiment, the set of OFDM symbols are starting from that UEdetects a channel indicator and until (the first symbol of) a slotformat indication (SFI) monitoring occasion, wherein the SFI monitoringoccasion is the next or the nearest SFI monitoring occasion after the UEdetects the channel indicator. If the (pre-)configured resource iswithin the set of OFDM symbols, whether the UE performs the transmissionor reception on the (pre-)configured resource could be determined basedon slot format or transmitted direction of the (pre-)configured resourceindicated by RRC signaling(s). If transmitted direction of OFDM symbolof the (pre-)configured resource indicated by RRC signaling(s) isflexible and/or downlink, the UE could perform the configured receptionon the (pre-)configured resource. Furthermore, if transmitted directionof OFDM symbol of the (pre-)configured resource indicated by RRCsignaling(s) is flexible and/or uplink, the UE could perform theconfigured transmission on the (pre-)configured resource.

In one embodiment, if the UE is configured to perform transmission onthe (pre-)configured resource, the UE could perform a channel accessprocedure or LBT scheme before the (pre-)configured resource. If achannel access procedure or LBT scheme before the (pre-)configuredresource, performed by the UE, is successful, the UE could perform theconfigured transmission on the (pre-)configured resource. If channelaccess procedure/LBT scheme before the (pre-)configured resource,performed by the UE, is not successful, the UE may not perform theconfigured transmission on the (pre-)configured resource.

In one embodiment, a network could configure a UE to performtransmission or reception on a (pre-)configured resource. If the(pre-)configured resource is within a set of OFDM symbols, the networkcould perform reception or transmission on the (pre-)configuredresource. The set of OFDM symbols could be starting from the OFDM symbolwhere the network transmits a channel indicator until a (next) SFImonitoring occasion, wherein the SFI monitoring occasion is a next orthe nearest SFI monitoring occasion after the UE detects the channelindicator.

In one embodiment, if the (pre-)configured resource is within the set ofOFDM symbols, whether the network performs transmission or reception onthe (pre-)configured resource could be determined based on slot format,transmitted direction, or functionality of the (pre-)configured resourceindicated by RRC signaling(s). If transmitted direction/functionality ofOFDM symbol of the (pre-)configured resource indicated by RRCsignaling(s) is flexible and/or downlink, the network could perform theconfigured transmission on the (pre-)configured resource. Furthermore,if transmitted direction/functionality of OFDM symbol of the(pre-)configured resource indicated by RRC signaling(s) is flexibleand/or uplink, the network could perform the configured reception on the(pre-)configured resource.

In one embodiment, the RRC signaling(s) could be one or a combination offollowing parameter, tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, tdd-UL-DL-ConfigDedicated. Theconfigured transmission could be configured grant transmission or grantfree transmission, SRS transmission, report of configured downlinkmeasurement, or uplink transmission. The configured reception could alsobe control resource set (CORESET) monitoring, downlink reference signalmeasurement, CSI-RS (Channel State Information-Reference Signal)measurement, SS-PBCH (Synchronization Signal-Physical Broadcast Channel)block measurement, or SPS-PDSCH (Semi Persistent Scheduling-PhysicalDownlink Shared Channel) reception.

In one embodiment, the UE could be configured to receive SFIperiodically. The UE could also be configured for periodic SFImonitoring occasion. The UE may not receive and/or monitor a slot formatindication (SFI) on a SFI monitoring occasion during a period or outsidea COT from the network. The period may start from an ending symbol ofone or last channel occupation and ending before the UE receives thechannel indicator. An example of the period is illustrated in FIG. 10 .

In one embodiment, if the UE does not receive a SFI on a SFI monitoringoccasion after the UE detects the channel indicator, the UE may assumethat the SFI is missed or the SFI is not detected, or the UE may notperform the configured transmission and/or the configured receptionexcept for performing (periodical) CORESET monitoring. If the UE doesnot receive a SFI on a SFI monitoring occasion before the UE detects thechannel indicator, wherein the SFI indicates slot format of the set ofOFDM symbol(s), the UE could ignore the missed SFI.

In one embodiment, a SFI received in an SFI monitoring occasion at leastcould indicate slot format of slots beginning from the SFI monitoringoccasion to next SFI monitoring occasion. A slot format indication (SFI)could be carried by or indicated in a downlink control information(DCI). The DCI could be DCI format 2_0. The SFI monitoring occasion(s)could be configured by indicating a periodicity and an offset. A SFIcould indicate slot format(s) of one or more than one slot.

In one embodiment, the channel indicator could indicate a starting of atime duration. The time duration could be the network's channeloccupancy time (COT). Within the time duration, the network couldperform transmission without performing another one channel accessprocedure or another one channel access procedure with random accessmechanism after the network performs a channel access procedure or LBTscheme (successfully).

In one embodiment, the channel indicator could be used for indicating achannel occupation or a channel occupation time. The UE may assume anetwork's COT starts from OFDM symbol where the UE receives the channelindicator. The UE may also assume an OFDM symbol where the UE receivesthe channel indicator is within network's COT. A network's COT couldstart earlier than the network transmits the channel indicator.

In one embodiment, the channel indicator could be a reference signal, or(one of) DMRS of CORESET, or a common signal, or a group common signal.The network could transmit the channel indicator if/after/once thenetwork occupied the channel or performs channel access procedure or LBTschemes successfully. If/after the UE detects the channel indicator, theUE could be aware of starting of the network's COT. If/after the UEdetects the channel indicator, the UE could ignore SFI miss whendetermining slot format, transmitted direction, or functionality of(slot(s) covering) the set of OFDM symbol(s), wherein the SFI missoccurs on an SFI monitoring occasion before the UE detects the channelindicator. If/after the UE detects the channel indicator, the UE couldperform preconfigured transmission or reception on the set of OFDMsymbol(s), even the SFI is not detected on an SFI monitoring occasionbefore the UE detects the channel indicator.

In one embodiment, the UE may perform transmission or reception on anunlicensed cell and/or a licensed cell. Furthermore, the network mayperform transmission or reception on an unlicensed cell and/or alicensed cell.

In one embodiment, a channel occupation could mean that a wireless nodeperform transmission in unlicensed spectrum and/or unlicensed channelfor a time period after a successful channel access procedure and/or LBTscheme. The time period could be a channel occupation time, where thewireless node can perform transmission (continuously). The time periodcould also be a channel occupation time, where the wireless node canperform transmission without performing another channel access procedureand/or LBT scheme. A channel occupation/a channel occupation time couldbe used to stand for a channel occupancy/a channel occupancy time.

In one embodiment, a UE detects a channel occupation (time) from or bythe network could mean the UE detects or realizes that the network(currently) is allowed to perform transmission (continuously) for thetime period (channel occupation time) after a successfully channelaccess procedure and/or LBT scheme.

Embodiment 2—A UE could be configured with periodic slot formatindication (SFI) monitoring occasion(s) to receive slot formatindication (SFI). Alternatively, a UE could be configured to receiveslot format indication (SFI) in a periodic manner. If/after the UEdetects or receives a channel indicator, the UE could receive a specialSFI on an occasion, wherein the occasion is not the configured SFImonitoring occasion. The special SFI could be a SFI-related signal.

In one embodiment, in the same slot where the UE detects and/or receivesa channel indicator, the UE may (expect to) receive a special SFI.If/after the UE detects and/or receives a channel indicator, the UEcould receive a special SFI on an occasion. The special SFI may not betransmitted periodically or may be transmitted aperiodically. In oneembodiment, the special SFI could be an event triggered transmission,e.g. transmitted when or after network performs a successful channelaccess procedure to transmit in unlicensed spectrum.

In one embodiment, a network could configure or indicate a UE periodicSFI monitoring occasion. If the network performs channel accessprocedure or LBT scheme successfully, the network may transmit a channelindicator. The channel indicator could be transmitted on beginning ofthe network's channel occupancy time (COT). The channel indicator couldalso be transmitted after the first allowable transmission boundary fromthe beginning of the network's COT. If/after the network transmits thechannel indicator, the network could transmit a special SFI, which maybe transmitted on a control resource set (CORESET). In one embodiment,the special SFI may be transmitted on an occasion. The occasion mayoccur after the network transmits the channel indicator. Morespecifically, the occasion may occur after the network transmits thechannel indicator and before a next or the nearest SFI monitoringoccasion, wherein the next or the nearest SFI monitoring occasion islocated after the channel indicator.

If the network performs channel access procedure or LBT schemesuccessfully, the network may transmit a channel indicator and/or aspecial SFI on a control resource set (CORESET). Furthermore, if thenetwork performs channel access procedure or LBT scheme successfully,the network transmits a special SFI on an occasion.

In one embodiment, the occasion may not be the configured (periodical)SFI monitoring occasion. The occasion is not the configured (periodical)SFI monitoring occasion. The occasion could be a (starting position of)control resource set (CORESET) and/or a search space (monitoringoccasion) after the UE receives the channel indicator, or after thenetwork performs channel access procedure or LBT scheme successfully.Furthermore, the occasion could be the next or the nearest CORESETand/or search space (monitoring occasion), after the UE receives thechannel indicator or after the network performs channel access procedureor LBT scheme successfully. The occasion could also be before the(periodical) SFI monitoring occasion(s), which occurs after the UEreceives the channel indicator, or after the network transmits thechannel indicator. For example, in FIG. 11 , the specific SFI could betransmitted in the CORESET/monitoring occasion, which is not the(preconfigured) periodic SFI monitoring occasion.

In one embodiment, the occasion could occupy a time domain resourcesstarting from the OFDM symbol, where the UE receives the channelindicator. The occasion could also occupy a time domain resources endinguntil the first OFDM symbol of a (periodical) SFI monitoring occasion(firstly) occurring after the OFDM symbol, where the UE receives thechannel indicator. In addition, the occasion could occupy a time domainresources comprising consecutive OFDM symbols.

In one embodiment, the occasion could be on a first allowabletransmission boundary for transmitting physical channel and/or RS withinthe network's COT in the unlicensed serving cell, wherein thetransmitted physical channel and/or RS is receivable or decodable forserved UE(s). The occasion could also be starting from a first allowabletransmission boundary for transmitting physical channel and/or RS withinthe network's COT in the unlicensed serving cell, wherein thetransmitted physical channel and/or RS is receivable or decodable forserved UE(s).

In one embodiment, the (periodical) SFI monitoring occasion could be anext or the nearest configured SFI monitoring occasion after the UEreceives the channel indicator. The CORESET and/or the search spacecould be the CORESET and/or the search space configured for receivinga/the SFI. Furthermore, the CORESET and/or the search space could be anext or the nearest CORESET and/or the search space after the UEreceives the channel indicator. In one embodiment, the special SFI couldindicate slot format at least from the OFDM symbol where the UE receivesthe channel indicator or the special SFI until next (available) SFImonitoring occasion.

In one embodiment, the UE could assume slot format(s) of slot(s) ortransmitted direction/functionality of a set of OFDM symbols based onRRC signaling(s), wherein the set of OFDM symbols are starting from (asymbol) where the UE receives the channel indicator and until the firstsymbol of timing resources of the CORESET.

In one embodiment, the occasion could occur in the middle of a slot(i.e. not in the first 2 or 3 OFDM symbols of a slot), or in thebeginning of a slot (e.g. starting from the first symbol of a slot). TheCORESET and/or a search space associated with the CORESET or theoccasion may not be transmitted and/or monitored in a licensed servingcell or licensed spectrum.

In one embodiment, if the UE does not receive the special SFI, the UEmay consider that SFI miss or the special SFI is not detected on OFDMsymbols starting from beginning of the occasion until next or thenearest SFI monitoring occasion, or the UE may not (be allowed to)perform configured transmission or reception except for (periodical)CORESET monitoring on a set of OFDM symbols starting from (the end of)the occasion until next or the nearest SFI monitoring occasion. The nextor the nearest SFI monitoring occasion may occur inside the network'sCOT.

In one embodiment, the UE may not receive a slot format indication (SFI)on a SFI monitoring occasion during a period. The period could bestarting from ending position of last COT and ending before the UEreceives the channel indicator. An example of the period is in FIG. 10 .

In one embodiment, if the UE does not receive a SFI on a (periodical)SFI monitoring occasion after the UE detects the channel indicator, theUE may assume that the SFI is missed or the SFI is not detected, or theUE may not perform the configured transmission and/or the configuredreception except for performing (periodical) CORESET monitoring.Furthermore, if the UE does not receive a SFI on a (periodical) SFImonitoring occasion before the UE detects the channel indicator, whereinthe SFI indicates slot format of the set of OFDM symbol(s), the UE couldignore the missed SFI.

In one embodiment, a SFI received in an (periodical) SFI monitoringoccasion could at least indicate slot format of slots from the SFImonitoring occasion to next SFI monitoring occasion. A slot formatindication (SFI) could be carried by or indicated in a downlink controlinformation (DCI). (Periodical) SFI monitoring occasion(s) could beconfigured by indicating a periodicity and an offset. A SFI couldindicate slot format(s) of one or more than one slot. The channelindicator could indicate (starting of) a network's channel occupancytime (COT).

Embodiment 3—If a UE is configured to receive or monitor slot formatindication (SFI) in an unlicensed serving cell, whether the UE monitorsor receives SFI could be determined based on a channel indicator. In oneembodiment, the UE may not monitor or receive SFI before the UE receivesor detects the channel indicator, and/or after the end of a channeloccupation time from the network or the UE in the unlicensed servingcell and until the UE receives or detects the channel indicator.

Before the UE receives or detects the channel indicator, the UE mayassume slot format, transmitted direction, functionality of slots, orOFDM symbols is flexible. Furthermore, after the end of a channeloccupation time from the network or the UE in the unlicensed servingcell and until the UE receives or detects the channel indicator, the UEmay assume slot format, transmitted direction, functionality of slots,or OFDM symbols is flexible. In one embodiment, the UE may assume slotformat, transmitted direction, functionality of slots, or OFDM symbolsis flexible, which is located after the end of a channel occupation timefrom the network or the UE in the unlicensed serving cell and until theUE receives or detects the channel indicator. Before the UE receives ordetects the channel indicator, the UE could perform monitoring thechannel indicator. After the end of a channel occupation time from thenetwork or the UE in the unlicensed serving cell and until the UEreceives or detects the channel indicator, the UE could performmonitoring and/or detecting the channel indicator.

In one embodiment, the UE may not consider that SFI is not detectedbefore the UE receives or detects the channel indicator, and/or afterthe end of a channel occupation time from the network or the UE in theunlicensed serving cell and until the UE receives or detects the channelindicator. If/after the UE receives/detects the channel indicator, theUE could monitor or receive SFI on configured SFI monitoring occasionduring a time duration (or a COT).

In one embodiment, the UE may not perform configured physical channeland/or RS reception (in a flexible symbol) outside a COT (except formonitoring for the channel indicator). Furthermore, the UE may notperform configured physical channel and/or RS transmission (in aflexible symbol) outside a COT.

In one embodiment, the UE may not perform configured physical channeland/or RS reception (in a flexible symbol which is) after the end of achannel occupation time from the network or the UE in the unlicensedserving cell and until the UE receives or detects the channel indicator(except for monitoring for the channel indicator). Furthermore, the UEmay not perform configured physical channel and/or RS transmission (in aflexible symbol which is) after the end of a channel occupation timefrom the network or the UE in the unlicensed serving cell and until theUE receives or detects the channel indicator.

For example, in FIG. 12 , assuming a UE is configured to receive DCIformat 2_0 (SFI) in an unlicensed cell every 2 slots and assuming slotoffset is 0. In this example, before the UE receives and/or detectschannel indicator in slot #n+3, one way is that the UE does not monitorSFI monitoring occasion in slot #n and in slot #n+2. Another way is thatthe UE could perform SFI monitoring in slot #n and slot #n+2. In FIG. 12, before the UE receives and/or detects channel indicator in slot #n+7,the UE monitors SFI monitoring occasion in slot #n+6. Alternatively,before the UE receives and/or detects channel indicator in slot #n+7,the UE does not monitor SFI monitoring occasion in slot #n+6.

In one embodiment, the UE could receive a configuration to monitorand/or receive slot format indication (SFI) in an unlicensed servingcell. The configuration may indicate at least one of the followings: aperiodicity, a slot offset (the slot offset may not be configured to belarger than a COT), a quantity of consecutive monitoring occasions, abit-map, or (periodic) monitoring occasions of SFI.

In one embodiment, if/after the UE receives the channel indicator, theslot offset could be applied relative to a slot, where the UE receivesthe channel indicator. Monitoring occasion for the signal based on theconfiguration could be applied relative to a slot, where the UE receivesthe channel indicator. If/after the UE receives the channel indicator inslot with slot index #n, a monitoring occasion with slot index #m forthe signal within a time period shall satisfy that mod(m-n, theperiodicity)=the slot offset (if the quantity of consecutive monitoringoccasions is not configured).

In one embodiment, if/after the UE receives the channel indicator inslot with slot index #n, monitoring occasion(s) for the signal within atime period (shall) starts from or occurs in a slot with slot index #msatisfying that mod(m-n, the periodicity)=the slot offset and there arecontiguous monitoring occasion(s) starting from slot #m (including themonitoring occasion in slot #m) as indicated by the quantity.

For example, in FIG. 13 , assuming configuration for DCI format 2_0could indicate that periodicity is 2 slots and slot offset is 0 and aquantity of consecutive monitoring occasions (for a periodicopportunity) is not configured. In this example, if the UE receives thechannel indicator in slot #n+3, the UE may assume slot #n+3 is areference slot for applying the configuration for receiving DCI format2_0 within a COT (slot #n+3 to slot #n+5). In other words, if the UEreceives the channel indicator, a monitoring occasion of DCI format 2_0(i.e. slot #m) within a time period (or COT from UE's view) (shall)satisfy that mod (slot #m-slot #n+3, 2)=0. In this example, the UE couldhave at least one monitoring occasion (i.e. in slot #n+3, and in slot#n+5) within a time period (or COT from UE's view) for receiving a DCIformat 2_0. Similarly, in FIG. 13 , if the UE receives the channelindicator in slot #n+7, the UE could have at least one monitoringoccasion (i.e. in slot #n+7) within a time period (COT from UE's view)for receiving a DCI format 2_0.

In FIG. 13 , for a monitoring occasion outside a time period, the UEcould monitor or detect DCI format 2_0 based on the configuration forDCI format 2_0. For a monitoring occasion outside a time period, theconfiguration for DCI format 2_0 is applied referenced based on a slot.Preferably, the slot could be with a physical or logical slot index “0”.In this example, assuming slot #n could be the (referenced) slot foroutside a time period. Alternatively, the configuration for a monitoringoccasion outside a time period (e.g., a second configuration orparameters) is another configuration, which is different from theconfiguration for a monitoring occasion inside a time period (e.g., afirst configuration or parameters). When/after a UE detects or receivesa channel indicator (e.g., inside a time period), the UE receives DCIformat 2_0 in the time period based on the first configuration orparameters. In one embodiment, the configuration for a monitoringoccasion outside a time period (e.g., the second configuration orparameters) may be referenced to the slot. The configuration for amonitoring occasion inside a time period (e.g., the first configurationor parameters) may be referenced to the slot (which is the same as theoutside example). In one embodiment, the configuration for a monitoringoccasion inside a time period may indicate a different periodicityand/or slot offset and/or enabled/configured a quantity of consecutivemonitoring occasion(s) from the configuration for a monitoring occasionoutside a time period. For example, the configuration for a monitoringoccasion inside a time period may indicate a quantity of consecutivemonitoring occasion(s) while the configuration for a monitoring occasionoutside the time period does not indicate a quantity of consecutivemonitoring occasion(s). In another embodiment, the configuration for amonitoring occasion inside a time period could be the same thatperiodicity is 2 slots and slot offset is 0 and a quantity ofconsecutive monitoring occasions is not configured. In other words, theUE could monitor DCI format 2_0 in slot #n, slot #n+2, slot #n+6.Another alternative is that the UE may not monitor/detect a DCI format2_0 and/or monitoring occasion(s) outside the time period.

In one embodiment, before the UE receives the channel indicator, and/orafter the end of a time period and until receiving the channelindicator, the UE may not monitor/detect DCI format 2_0. Furthermore,before the UE receives the channel indicator, the UE could monitor ordetect DCI format 2_0 or the signal on a monitoring occasion with slotindex #m satisfying that mod(m, the periodicity)=the slot offset (if thequantity of consecutive monitoring occasions is not configured). In oneembodiment, slot index is physical slot index or logical slot index. Inaddition, after the end of a time period and until receiving the channelindicator, the UE could monitor/detect DCI format 2_0 or the signal on amonitoring occasion with slot index #m satisfying that mod(m, theperiodicity)=the slot offset (if the quantity of consecutive monitoringoccasions is not configured).

In one embodiment, before the UE receives the channel indicator, the UEcould monitor or detect DCI format 2_0 or the signal on a monitoringoccasion starting from or occurs in a slot with slot index #m satisfyingthat mod(m, the periodicity)=the slot offset and there are contiguousmonitoring occasion(s) starting from slot #m (including the monitoringoccasion in slot #m) as indicated by the quantity, if indicated.Furthermore, after the end of a time period and until receiving thechannel indicator, the UE could monitor or detect DCI format 2_0 or thesignal on a monitoring occasion starting from or occurs in a slot withslot index #m satisfying that mod(m, the periodicity)=the slot offsetand there are contiguous monitoring occasion(s)starting from slot #m(including the monitoring occasion in slot #m) as indicated by thequantity, if indicated.

In one embodiment, if/after a network performs channel access procedureor LBT scheme successful, the network could transmit a channelindicator. Furthermore, if and/or after the network transmits thechannel indicator or performs a channel access procedure successfully,the network may perform transmission and/or reception during a timeduration. The time duration could be the network's channel occupancytime (COT). The time duration may be smaller than or located within thenetwork's channel occupancy time (COT). The time duration could startfrom an OFDM symbol, where the UE detects the channel indicator.

In one embodiment, ending position of the time duration could bedetermined based on either an indication for the UE indicating endingposition or a maximum value or a (actual) channel occupation time usedfor the network after a (successful) channel access procedure and/or LBTscheme. The maximum value could refer to maximum channel occupancy timeof a (channel access or LBT) priority class of the network. The networkcould transmit the indication to a UE for indicating ending position ofthe time duration. The channel indicator could indicate (starting of) anetwork's channel occupancy time (COT).

Embodiment 4—A network could perform transmission or reception in anunlicensed (serving) cell. The network may not (be allowed to) configureor indicate slot format for slots or symbols in the unlicensed (serving)cell by RRC signaling(s). A UE could perform transmission or receptionin an unlicensed (serving) cell. The UE may not expect to be configuredwith or be indicated slot format of slots or symbols by RRC signaling(s)for the unlicensed (serving) cell. In one embodiment, the network maynot (be allowed to) indicate a UE that which functionality or state ortransmission direction of a slot(s) or OFDM symbol(s) by RRC signaling.In one embodiment, the network may (be allowed to) indicate dynamic SFIindication related configuration to the UE. In one embodiment, the UEmay not be indicated that which functionality or state or transmissiondirection of a slot or OFDM symbol by RRC signaling. In one embodiment,in response to not being indicated which functionality or state ortransmission direction of a slot or symbol by RRC signaling, the UE mayconsider or assume that the slot or symbol is flexible unless further(dynamic) SFI indication.

All or some of above embodiments can be combined to form a newembodiment.

FIG. 15 is a flow chart 1500 according to one exemplary embodiment fromthe perspective of a UE (User Equipment). In step 1505, the UE performstransmission and/or reception in a serving cell, wherein the servingcell is in unlicensed spectrum. In step 1510, the UE is configured toreceive SFI on periodic SFI monitoring occasion(s), wherein periodic SFImonitoring occasion(s) is (pre-)configured by a network. In step 1515,in response to receiving and/or detecting a channel indicator, the UEmonitors and/or detects a first SFI-related signal on a first occasion,wherein the first occasion is not one of (pre-)configured periodic SFImonitoring occasion(s).

In one embodiment, in response to receiving and/or detecting a channelindicator, the UE could monitor and/or detect a first SFI-related signalon a first occasion, wherein the first occasion is not one of(pre-)configured SFI monitoring occasion(s). The first SFI-relatedsignal could indicate slot format or functionality at least forsymbol(s) starting from a OFDM symbol where the UE receives the firstSFI-related signal until the start of next available SFI monitoringoccasion. The UE could monitor and/or detect a second SFI-related signalon a second occasion, wherein the second occasion is among one of(pre-)configured SFI monitoring occasion(s). A SFI monitoring occasioncould mean a starting position to monitor a SFI-related signal, or atime-frequency resource to monitor a SFI-related signal. The firstoccasion may occur on or start from a slot or OFDM symbol, where the UEreceives the channel indicator. The first occasion could be (startingposition of) the most recent CORESET (Control Resource Set) and/orsearch space monitoring occasion after the UE receives the channelindicator.

In one embodiment, the channel indicator could indicate or implyoccurring of a network's channel occupancy time (COT). The channelindicator could be a DMRS (Demodulation Reference Signal) of CORESET ora common signal or a group common signal.

In one embodiment, in response to detecting the channel indicator, theUE may be allowed to perform preconfigured transmission or receptionwithin a set of OFDM symbol(s) located after the channel indicator,regardless of whether or not the UE detects SFI on periodic SFImonitoring occasion(s) before the channel indicator.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) to performtransmission and/or reception in a serving cell, wherein the servingcell is in unlicensed spectrum, (ii) to be configured to receive SFI onperiodic SFI monitoring occasion(s), wherein periodic SFI monitoringoccasion(s) is (pre-)configured by a network, and (iii) to, in responseto receiving and/or detecting a channel indicator, monitor and/or detecta first SFI-related signal on a first occasion, wherein the firstoccasion is not one of (pre-)configured periodic SFI monitoringoccasion(s). Furthermore, the CPU 308 can execute the program code 312to perform all of the above-described actions and steps or othersdescribed herein.

FIG. 16 is a flow chart 1600 according to one exemplary embodiment fromthe perspective of a UE. In step 1605, the UE receives configuration ofa first serving cell and (configuration of) a second serving cell from anetwork, wherein the first serving cell is in licensed spectrum and thesecond serving cell is in unlicensed spectrum. In step 1610, the UEreceives configuration indicating the UE to monitor and/or receive a DCI(Downlink Control Information) periodically in the first serving cell,wherein the DCI indicates a first SFI (Slot Format Indication) for thefirst serving cell and a second SFI for the second serving cell. In step1615, the UE ignores the second SFI indicated in the DCI, if the DCI isreceived before the UE detects or is indicated that the network starts achannel occupancy time.

In one embodiment, the UE could discard the second SFI indicated in theDCI, if the DCI is received before the UE detects or is indicated thatthe network starts a channel occupancy time. Furthermore, the UE couldignore or discard the second SFI indicated in the DCI, if the DCI isreceived before the UE detects or is indicated that the network starts achannel occupancy time, and if the second SFI indicates slot formatvalue, which is not a particular value. The particular value couldindicate that the UE is allowed to perform preconfigured transmission orreception. In one example, the particular value may be 255 or thelargest slot format value allowed to be indicated. In another example,the particular value may be a reserved value (e.g., 254).

In one embodiment, the UE could detect or be indicated that the networkstarts a channel occupancy time by receiving a channel indicator. Thechannel indicator could be a DMRS of a CORESET (Control Resource Set) ora common signal or a group common signal. Furthermore, the channelindicator could be transmitted by the network after or in response tothe network occupying an unlicensed channel or performing a channelaccess procedure successfully.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) to receiveconfiguration of a first serving cell and (configuration of) a secondserving cell from a network, wherein the first serving cell is inlicensed spectrum and the second serving cell is in unlicensed spectrum,(ii) to receive configuration indicating the UE to monitor and/orreceive a DCI periodically in the first serving cell, wherein the DCIindicates a first SFI for the first serving cell and a second SFI forthe second serving cell, and (iii) to ignore the second SFI indicated inthe DCI, if the DCI is received before the UE detects or is indicatedthat the network starts a channel occupancy time. Furthermore, the CPU308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

FIG. 17 is a flow chart 1700 according to one exemplary embodiment fromthe perspective of a network. In step 1705, the network performstransmission/reception on an unlicensed cell. In step 1710, the networkconfigures a UE to perform a transmission or reception on a(pre-)configured resource. In step 1715, the network configures a UE toreceive SFI on periodic SFI monitoring occasion, wherein if the(pre-)configured resource is within a set of OFDM symbol, whether thenetwork performs the reception or transmission on the (pre-)configuredresource is determined based on transmitted direction or slot format ofthe (pre-)configured resource indicated by RRC signaling(s), wherein theset starts from beginning of the network's COT until beginning of a SFImonitoring occasion, and wherein the SFI monitoring occasion is the mostnear SFI monitoring occasion after the network's COT.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network(i) to perform transmission/reception on an unlicensed cell, (ii) toconfigure a UE to perform a transmission or reception on a(pre-)configured resource, (iii) to configure a UE to receive SFI onperiodic SFI monitoring occasion, wherein if the (pre-)configuredresource is within a set of OFDM symbol, whether the network performsthe reception or transmission on the (pre-)configured resource isdetermined based on transmitted direction or slot format of the(pre-)configured resource indicated by RRC signaling(s), wherein the setstarts from beginning of the network's COT until beginning of a SFImonitoring occasion, and wherein the SFI monitoring occasion is the mostnear SFI monitoring occasion after the network's COT. Furthermore, theCPU 308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

FIG. 18 is a flow chart 1800 according to one exemplary embodiment fromthe perspective of a UE. In step 1805, the UE performstransmission/reception on an unlicensed cell. In step 1810, the UE isconfigured to perform transmission or reception on a (pre-)configuredresource. In step 1815, the UE is configured to receive slot formatindication (SFI) on periodic SFI monitoring occasion, wherein if the(pre-)configured resource is within a set of OFDM symbol, whether the UEperforms the reception or transmission on the (pre-)configured resourceis determined based on transmitted direction/slot format of the(pre-)configured resource indicated by RRC signaling(s), wherein the setstarts from the OFDM symbol where the UE receives a channel indicatoruntil beginning of a SFI monitoring occasion, and wherein the SFImonitoring occasion is the most near SFI monitoring occasion after thenetwork's COT.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) to performtransmission/reception on an unlicensed cell, (ii) to be configured toperform transmission or reception on an (pre-)configured resource, and(iii) to be configured to receive slot format indication (SFI) onperiodic SFI monitoring occasion, wherein if the (pre-)configuredresource is within a set of OFDM symbol, whether the UE performs thereception or transmission on the (pre-)configured resource is determinedbased on transmitted direction/slot format of the (pre-)configuredresource indicated by RRC signaling(s), wherein the set starts from theOFDM symbol where the UE receives a channel indicator until beginning ofa SFI monitoring occasion, and wherein the SFI monitoring occasion isthe most near SFI monitoring occasion after the network's COT.Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

In the context of the embodiments illustrated in FIGS. 17 and 18 anddescribed above, in one embodiment, the RRC signaling(s) could be one orcombination of following parameters: tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated. Theconfigured transmission could be configured grant transmission, grantfree transmission, SRS transmission, report of configured downlinkmeasurement, or uplink transmission. The configured reception could alsobe CORESET monitoring, downlink reference signal measurement, CSI-RSmeasurement, SS-PBCH block measurement, or SPS-PDSCH reception.

In one embodiment, if the UE does not receive a SFI on a SFI monitoringoccasion after the UE detects the channel indicator, the UE may assumeSFI miss or SFI is not detected. Furthermore, if the UE does not receivea SFI on a SFI monitoring occasion after the UE detects the channelindicator, the UE may not perform the configured transmission and/or theconfigured reception except perform CORESET monitoring. In addition, ifthe UE does not receive a SFI on a SFI monitoring occasion before the UEdetects the channel indicator wherein the SFI indicates slot format ofthe set of OFDM symbol(s), the UE could ignore SFI miss.

In one embodiment, a SFI received in an SFI monitoring occasion could atleast indicates slot format of slots from the SFI monitoring occasion tonext SFI monitoring occasion. A SFI could be carried by a downlinkcontrol information (DCI). The DCI could be DCI format 2_0. The SFImonitoring occasion(s) could be configured by periodicity and offset ofDCI format 2_0. A SFI could indicate slot format of one or more than oneslot.

In one embodiment, the channel indicator could indicate (starting of) anetwork's channel occupancy time (COT). The channel indicator could be areference signal, (one of) DMRS of CORESET, a common signal, or a groupcommon signal.

In one embodiment, the network could transmit the channel indicatorif/after/once the network occupied the channel. If/after the networkperforms channel access procedure/LBT schemes successfully, the networkcould transmit the channel indicator. If/after the UE detects thechannel indicator, the UE could be aware of (starting of) the network'sCOT. Furthermore, if/after the UE detects the channel indicator, the UEcould ignore SFI miss when determining slot format of the set of OFDMsymbol(s). In addition, if/after the UE detects the channel indicator,the UE could ignore a SFI transmitted on an SFI monitoring occasionbefore the UE detects the channel indicator. Also, if/after the UEdetects the channel indicator, the UE could assume slot format of theset of OFDM symbol is determined based on the RRC signaling(s).

FIG. 19 is a flow chart 1900 according to one exemplary embodiment fromthe perspective of a network. In step 1905, the network performstransmission/reception on an unlicensed cell. In step 1910, the networkconfigures a UE to receive SFI on periodic SFI monitoring occasion. Instep 1915, if the network performs channel access procedure or LBTscheme successfully, the network transmits a SFI on an occasion, whereinthe occasion is not the configured SFI monitoring occasion.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network(i) to perform transmission/reception on an unlicensed cell, (ii) toconfigure a UE to receive SFI on periodic SFI monitoring occasion, and(iii) to transmit a SFI on an occasion if the network performs channelaccess procedure or LBT scheme successfully, wherein the occasion is notthe configured SFI monitoring occasion. Furthermore, the CPU 308 canexecute the program code 312 to perform all of the above-describedactions and steps or others described herein.

FIG. 20 is a flow chart 2000 according to one exemplary embodiment fromthe perspective of a UE. In step 2005, the UE performs transmission orreception on an unlicensed cell. In step 2010, the UE is configured toreceive slot format indication (SFI) on periodic SFI monitoringoccasion. In step 2015, if the UE receives or detects a channelindicator, the UE monitors a special SFI on an occasion, wherein theoccasion is not the configured SFI monitoring occasion.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) to performtransmission or reception on an unlicensed cell, (ii) to be configuredto receive slot format indication (SFI) on periodic SFI monitoringoccasion, and (iii) to monitor a special SFI on an occasion if the UEreceives or detects a channel indicator, wherein the occasion is not theconfigured SFI monitoring occasion. Furthermore, the CPU 308 can executethe program code 312 to perform all of the above-described actions andsteps or others described herein.

In the context of the embodiments illustrated in FIGS. 19 and 20 anddescribed above, the occasion could be a CORESET and/or a search spacemonitoring occasion after the UE receives the channel indicator or afterthe network performs channel access procedure or LBT scheme successful.The occasion could be the most recent CORESET and/or search spacemonitoring occasion after the UE receives the channel indicator, orafter the network performs channel access procedure or LBT schemesuccessful. The occasion could occur on slot/OFDM symbol, where the UEreceives the channel indicator or the special SFI. The occasion couldalso occur on middle of a slot, or the beginning of a slot.

In one embodiment, if the UE does not receive the special SFI, the UEmay consider SFI miss or not detect the SFI on OFDM symbols frombeginning of the CORESET until next (SFI) monitoring occasion. Also, ifthe UE does not receive the special SFI, the UE may not performconfigured transmission or reception except CORESET monitoring on OFDMsymbols from the CORESET until next (SFI) monitoring occasion.

In one embodiment, the configured transmission could be configured granttransmission, grant free transmission, SRS transmission, report ofconfigured downlink measurement, or uplink transmission. The configuredreception could also be CORESET monitoring, downlink reference signalmeasurement, CSI-RS measurement, SS-PBCH block measurement, or SPS-PDSCHreception.

In one embodiment, the channel indicator could indicate the starting ofa network's channel occupancy time (COT). The signal could be areference signal, (one of) DMRS of CORESET, a common signal, or a groupcommon signal.

In one embodiment, the network could transmit the channel indicatorif/after/once the network occupied the channel, and/or the networkperforms channel access procedure or LBT schemes successfully. If/afterthe UE detects the channel indicator, the UE could be aware of startingof the network's COT, and/or the UE could ignore SFI miss whendetermining slot format of the set of OFDM symbol(s). Furthermore,if/after the UE detects the channel indicator, the UE could ignore a SFItransmitted on an SFI monitoring occasion before the UE detects thechannel indicator, and/or the UE could assume slot format of the set ofOFDM symbol is determined based on the RRC signaling(s).

FIG. 21 is a flow chart 2100 according to one exemplary embodiment fromthe perspective of a network. In step 2105, the network performstransmission or reception on an unlicensed cell. In step 2110, thenetwork configures a UE to receive SFI periodically. In step 2115, if orafter the network performs channel access procedure or LBT schemesuccessful, the network transmits SFI on configured SFI monitoringoccasion during a time duration, wherein the time duration is thenetwork's COT.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network(i) to perform transmission or reception on an unlicensed cell, (ii) toconfigure a UE to receive SFI periodically, and (iii) to transmit SFI onconfigured SFI monitoring occasion during a time duration if or afterthe network performs channel access procedure or LBT scheme successful,wherein the time duration is the network's COT. Furthermore, the CPU 308can execute the program code 312 to perform all of the above-describedactions and steps or others described herein.

FIG. 22 is a flow chart 2200 according to one exemplary embodiment fromthe perspective of a UE. In step 2205, the UE performs transmission orreception on an unlicensed cell, wherein if the UE is configured toreceive or monitor a SFI, whether the UE monitors or receives the SFI isdetermined based on a channel indicator.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE to performtransmission or reception on an unlicensed cell, wherein if the UE isconfigured to receive or monitor a SFI, whether the UE monitors orreceives the SFI is determined based on a channel indicator.Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

In the context of the embodiments illustrated in FIGS. 21 and 22 anddescribed above, in one embodiment, if or after the network performschannel access procedure or LBT scheme successful, the network couldtransmit a channel indicator. Furthermore, before the network transmitsthe channel indicator, the network may not transmit the SFI. Inaddition, before the network performs channel access procedure or LBTscheme successful or before the network occupied a channel or medium,the network may not transmit the SFI.

In one embodiment, if or after the network transmits the channelindicator, the network could transmit SFI on configured SFI monitoringoccasion during a time duration. The time duration could start from OFDMsymbol, where the UE detects the channel indicator. Ending position ofthe time duration could be determined based on either an indication forthe UE indicating ending position or a maximum value. The maximum valuecould refer to maximum channel occupancy time of a (channel access orLBT) priority class of the network.

In one embodiment, the network could transmit the indication to a UE forindicating ending position of the time duration. The channel indicatorcould indicate the starting of a network's COT. The channel indicatorcould be a reference signal, or (one of) DMRS of CORESET, a commonsignal, and a group common signal.

In one embodiment, the network could transmit the channel indicator ifor after the network occupied the channel or if (or after) the networkperforms channel access procedure or LBT schemes successfully.

In one embodiment, if or after the UE detects the channel indicator, theUE could be aware of starting of the network's COT or the UE couldignore SFI miss when determining slot format of the set of OFDMsymbol(s). Furthermore, if or after the UE detects the channelindicator, the UE could ignore a SFI transmitted on an SFI monitoringoccasion before the UE detects the channel indicator, or the UE couldassume slot format of the set of OFDM symbol is determined based on theRRC signaling(s), the RRC signaling(s) could be one or a combination ofthe following parameters: tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated.

In one embodiment, the configured transmission could be configured granttransmission, grant free transmission, SRS transmission, report ofconfigured downlink measurement, or uplink transmission. The configuredreception could be control resource set (CORESET) monitoring, downlinkreference signal measurement, CSI-RS measurement, SS-PBCH blockmeasurement, or SPS-PDSCH reception.

In one embodiment, a SFI received in an SFI monitoring occasion could atleast indicate slot format of slots from the SFI monitoring occasion tonext SFI monitoring occasion. A SFI could be carried by a DCI. The DCIcould be DCI format 2_0. SFI monitoring occasion(s) could be configuredby periodicity and offset of DCI format 2_0. The SFI could indicate slotformat of one or more than one slot.

FIG. 23 is a flow chart 2300 according to one exemplary embodiment fromthe perspective of a network. In step 2305, the network performstransmission or reception on an unlicensed cell, wherein the network isnot allowed to configure slot format by RRC signaling(s).

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network toperform transmission or reception on an unlicensed cell, wherein thenetwork is not allowed to configure slot format by RRC signaling(s).Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

FIG. 24 is a flow chart 2400 according to one exemplary embodiment fromthe perspective of a UE. In step 2405, the UE performs transmission orreception on an unlicensed cell, wherein the UE does not expect to beconfigured with slot format by RRC signaling(s).

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE to performtransmission or reception on an unlicensed cell, wherein the UE does notexpect to be configured with slot format by RRC signaling(s).Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

In the context of the embodiments illustrated in FIGS. 23 and 24 anddescribed above, in one embodiment, the RRC signaling(s) could be one ora combination of following parameters: tdd-UL-DL-ConfigurationCommon,tdd-UL-DL-ConfigurationCommon2, and tdd-UL-DL-ConfigDedicated.

In one embodiment, the UE could be configured to receive SFIperiodically. The UE could receive SFI if or after the UE receives achannel indicator. Before the UE receives the channel indicator, the UEmay not receive SFI, and/or the UE could assume slot format of OFDMsymbols or slots is flexible. Furthermore, before the UE receives thechannel indicator, the UE could monitor for the channel indicator. Inaddition, before the UE receives the channel indicator, the UE may notperform configured transmission or reception except monitors for thechannel indicator.

In one embodiment, the network could indicate slot format by SFI. If orafter the network performs channel access procedure or LBT schemesuccessful, the network could transmit a channel indicator. If or afterthe network transmits the channel indicator, the network could transmitSFI on configured SFI monitoring occasion during the network's COT. Thechannel indicator could indicate starting of a network's COT. Thechannel indicator could be a reference signal, and (one of) DMRS ofCORESET, a common signal, or a group common signal.

In one embodiment, the network could transmit the channel indicator ifor after the network occupied the channel, or if or after the networkperforms channel access procedure or LBT schemes successfully. If orafter the UE detects the channel indicator, the UE could be aware ofstarting of the network's COT. Furthermore, if or after the UE detectsthe channel indicator, the UE could ignore SFI miss when determiningslot format of the set of OFDM symbol(s), and/or the UE could ignore aSFI transmitted on an SFI monitoring occasion before the UE detects thechannel indicator. In addition, if or after the UE detects the channelindicator, the UE could assume slot format of the set of OFDM symbol isdetermined based on the RRC signaling(s).

In one embodiment, a SFI received in an SFI monitoring occasion could atleast indicate slot format of slots from the SFI monitoring occasion tonext SFI monitoring occasion. A SFI could be carried by a DCI. The DCIcould be DCI format 2_0. SFI monitoring occasion(s) could be configuredby periodicity and offset of DCI format 2_0. The SFI could indicate slotformat of one or more than one slot.

In NR licensed band operation, a DCI format 2_0 could be configured bygNB to indicate one or more slot formats for one or more serving cells,which means SFI of one serving cell could be indicated by another oneserving cell. However, if SFI of an unlicensed cell is indicated byanother one serving cell, some ambiguous conditions may happen due totransmission uncertainty in the unlicensed cell.

For example, in FIG. 14 , assuming a UE is configured to receive DCIformat 2_0 in a NR licensed cell and there is a DCI format 2_0indicating SFI 1 for the NR licensed cell and SFI 2 for a NR unlicensedcell. In this example, if the first DCI format 2_0 occasion in FIG. 14is outside network's channel occupancy time, how UE treats the SFI 2received in the licensed cell. In a similar example, if the UE isconfigured to receive DCI format 2_0 in an unlicensed cell and there isa DCI format 2_0 indicating a SFI for a licensed cell and another SFIfor the unlicensed cell, SFI missing cases may occur frequently. Basedon above, how to handle SFI indication in or for unlicensed spectrumconsidering cross carrier or cell indication needs to be furtherstudied. Possible solutions for the issue are described below.

One general concept is that if a UE receives a slot format indication(SFI) and/or a slot format combination for an unlicensed serving cell,wherein the slot format indication and/or the slot format combination istransmitted in a licensed serving cell and outside a channel occupationtime in the unlicensed serving cell, the UE may perform a behavior. Inone embodiment, before the UE receives a channel indicator, if a UEreceives in a licensed serving cell a slot format indication (SFI)and/or a slot format combination for an unlicensed serving cell, the UEmay perform a behavior. The behavior could be that the UE may discard orignore the SFI or that the UE may buffer the SFI until next (available)SFI monitoring occasion or the UE receives a channel indicator or the UEdetects or be indicated a channel occupation. The behavior could also bethat the UE may apply the (buffered) SFI from (the beginning of) slot orOFDM symbol where the UE receives a channel indicator or the UE detectsa channel occupation by network or from next (available) SFI monitoringoccasion. Furthermore, the behavior could be that whether or not the UEapplies the SFI is determined based on a channel indicator.

In one embodiment, the channel indicator could be used for indicating(starting of) a channel occupation or a channel occupation time. Thechannel occupation time could be obtained by network or the UE.

Another general concept could be one or more limitation or restrictionmay be applied on a network when indicating a cross-cell SFI. Thenetwork may not be allowed to configure a serving cell indicating slotformat(s) for an unlicensed serving cell. Furthermore, the network maynot be allowed to configure that slot format(s) for an unlicensed cellis indicated by DCI format 2_0 received in a licensed cell.

In one embodiment, a network may not be allowed to configure DCI format2_0 transmitted in an unlicensed serving cell and indicating slotformat(s) for other serving cell(s), at least for licensed servingcells. Also, a network may not be allowed to configure DCI format 2_0transmitted in an unlicensed serving cell and cross-cell indicating slotformat(s) for other serving cell(s). In addition, a network may not beallowed to configure DCI format 2_0 transmitted in an unlicensed servingcell and indicating slot format(s) for licensed serving cell(s).

In one embodiment, if a network transmits slot format indication (SFI)for an unlicensed serving cell in a licensed serving cell beforeperforming channel access procedure or LBT scheme (successfully) in theunlicensed serving cell, the network is not allowed to indicate slotformat value(s) for the unlicensed serving cell other than a particularslot format value in the SFI. The particular slot format value couldindicate slot format value 255 or a slot format value intended forindicating slot structure in unlicensed spectrum.

Another general concept is for an unlicensed serving cell, the UE doesnot expect to receive a SFI indicating slot format value(s) other thanslot format values 255 before the UE receives a channel indicator orbefore the UE detects a channel occupation by network. In oneembodiment, after the end of a channel occupation (or last channeloccupation) and until the UE receives the channel indicator, the UE maynot apply the SFI for the unlicensed cell. Before the UE receives thechannel indicator, the UE may not apply slot format value other than 255for the unlicensed cell. Furthermore, after the end of a channeloccupation (or last channel occupation) and until the UE receives thechannel indicator, the UE may not apply slot format value other than 255for the unlicensed cell. After/if the UE receives the channel indicator,the UE could apply a slot format value 255 for the unlicensed cell.

In one embodiment, the channel indicator could indicate a startingposition of a time duration. The channel indicator could be transmittedwithin a time duration. The time duration could be the network's channeloccupancy time (COT).

Any concepts mentioned above can form or be combined to form anembodiment.

Embodiment 1—A UE communicates with a first cell and a second cell. TheUE could be configured to receive channel and/or signal in a first(serving) cell and/or in a second (serving) cell. Furthermore, the UEcould be configured to transmit channel and/or signal in the first(serving) cell and/or in the second (serving) cell.

The UE could be configured to receive a downlink control information(DCI) on periodic monitoring occasion(s) in the first cell. The DCIcould indicate or comprise a first slot format indication (SFI) and asecond SFI. The first SFI could indicate slot format for the first cell,and the second SFI could indicate slot format for the second cell.

In one embodiment, if the UE receives the DCI in the first cell beforethe UE detects or receives a channel indicator or before the UE detectsor be indicated a channel occupation, the UE may discard or ignore thesecond SFI. The UE may not expect to receive a DCI indicating the firstSFI and the second SFI in the first (serving) cell. Furthermore, the UEmay not expect to receive a DCI indicating the first SFI and the secondSFI in the first (serving) cell before the UE receives or detects achannel indicator or before the UE detects or be indicated a channeloccupation.

In one embodiment, if the UE receives the DCI in the first cell beforethe UE detects or receives a channel indicator or before the UE detectsor be indicated a channel occupation, the UE may buffer the second SFI.The UE may (also) buffer the second SFI until the next (available)monitoring occasion of the DCI or until the UE receives the channelindicator or the UE detects or be indicated a channel occupation.Furthermore, the UE may apply the second SFI if the UE receives thechannel indicator or the UE detects or be indicated a channeloccupation. An available SFI monitoring occasion could be a SFImonitoring occasion within a channel occupation time.

Slot format values in the second SFI could indicate slot format of oneor more than one slot starting from the slot where the UE receives theDCI. For example, assuming a UE is configured to receive a DCI format2_0 every 5 slots in a first cell and the DCI format 2_0 indicates afirst SFI and a second SFI. The first SFI indicates slot format(s) forthe first cell. The second SFI indicates slot format(s) for the secondcell. In this example, if the UE receives the DCI format 2_0 in slot #n,the second SFI indicates multiple slot format values as {0, 2, 5, 6, 7}and the UE receives a channel indicator and/or detects a channeloccupation in slot #n+2, the UE applies slot format value {5} for slot#n+2, slot format value {6} for slot #n+3, and slot format value {7} forslot #n+4. In a similar example, if the UE receives a channel indicatorand/or detects a channel occupation on OFDM symbol #m of slot #n+2, theUE applied a part of slot format value {5} for slot #n+2.

In one embodiment, the part could start from OFDM symbol #m to the lastOFDM symbol of slot format #n+2 or to symbol functionality of the lastOFDM symbol of slot format #n+2. Alternatively, the part could startfrom OFDM symbol #0 to OFDM symbol #13-m of slot format #n+2.Furthermore, the part could start from symbol functionality of OFDMsymbol #m to symbol functionality of OFDM symbol #13-m of slot format#n+2 or to symbol functionality of OFDM symbol #13 of slot format #n+2.

In one embodiment, a SFI could indicate a slot combination for a servingcell. A slot combination could comprise one or more than one slot formatvalue. Furthermore, a slot format value could indicate slot format of aslot. A slot format value could also indicate transmitted direction orfunctionality of each of OFDM symbols in a slot.

In one embodiment, the DCI could be DCI format 2_0. The first cell couldbe a licensed cell or an unlicensed cell, and the second cell could be alicensed cell or an unlicensed cell. In one embodiment, the first cellcould be a licensed cell, and the second cell could be an unlicensedcell.

In one embodiment, a SFI received in a monitoring occasion of the DCIcould at least indicate slot format of slots from the slot aligningbeginning of the monitoring occasion of the DCI to next monitoringoccasion of the DCI. The channel indicator could indicate (starting of)a network's channel occupancy time (COT). The UE may assume a network'sCOT starts from OFDM symbol where the UE receives the channel indicator.The channel indicator could also be a reference signal, (one of) DMRS ofCORESET, a common signal, or a group common signal. If/after the UEdetects the channel indicator, the UE may assume transmission/reception(on a time duration) is the same as licensed band/spectrum.

Embodiment 2—A network could serve a first cell and a second cell. Thenetwork could transmit channel and/or signal in a first (serving) celland/or in a second (serving) cell. The network could receive channeland/or signal in the first (serving) cell and/or in the second (serving)cell.

The network could transmit to a UE a downlink control information (DCI)on periodic and/or semi-persistent monitoring occasion in the firstcell. The network could configure a UE to receive a downlink controlinformation (DCI) on periodic and/or semi-persistent monitoring occasionin the first cell. The DCI could also indicate a first slot formatindication (SFI) and a second SFI. The first SFI could indicate slotformat for the first cell and the second SFI indicates slot format forthe second cell.

In one embodiment, the network may transmit the DCI in the first cellbefore the network performs a channel access procedure or LBT scheme(successfully). If a network transmits slot format indication (SFI) foran unlicensed cell in a licensed cell before performing channel accessprocedure or LBT scheme (successfully) in the unlicensed cell, thenetwork may not be allowed to indicate slot format value(s) for theunlicensed serving cell in the SFI, other than a particular slot formatvalue.

In one embodiment, for an unlicensed cell, the UE may not expect toreceive SFI indicating a slot format value other than the particularslot format values before the UE receives a channel indicator and/ordetects or be indicated the channel occupation time. The particular slotformat value could indicate one slot format value 255 or a slot formatvalue intended for slot structure in unlicensed spectrum.

In one embodiment, whether or not the UE applies the SFI for anunlicensed cell could be determined based on a channel indicator. Beforethe UE receives the channel indicator and/or detects or be indicated thechannel occupation (time), the UE may not apply SFI for the unlicensedcell. In particular, before the UE receives the channel indicator and/ordetects or be indicated the channel occupation time, the UE may notapply slot format value 255 for the unlicensed cell. After/if the UEreceives the channel indicator and/or detects or be indicated thechannel occupation time, the UE could apply slot format value 255 forthe unlicensed cell.

In one embodiment, the channel indicator could indicate (starting of) anetwork's channel occupancy time (COT). The channel indicator could be areference signal, (one of) DMRS of CORESET, a common signal, or a groupcommon signal. If/after the UE detects the channel indicator, the UE mayassume transmission/reception (within a time duration) is the same aslicensed band/spectrum.

Embodiment 3—A network could configure or indicate slot formatindication (SFI) for one or more than one (serving) cells by a downlinkcontrol information (DCI). If the DCI is transmitted in a licensed cell,the network may not be allowed to configure/indicate an SFI for anunlicensed cell in the DCI. If the DCI is transmitted in an unlicensedcell, the network may not be allowed to indicate an SFI for a servingcell not operated in an unlicensed spectrum. Alternatively, if the DCIis transmitted in an unlicensed cell, the network may be allowed toindicate an SFI for a serving cell not operated in an unlicensedspectrum.

In one embodiment, the network may not be allowed to configure alicensed (serving) cell indicating or transmitting an SFI for anunlicensed cell. Furthermore, the network may not be allowed toconfigure an unlicensed (serving) cell indicating or transmitting an SFIfor a (serving) cell not operated in unlicensed spectrum.

In one embodiment, if a network configures a UE to receive a DCI format2_0 in an unlicensed (serving) cell, the network may not be allowed toconfigure that SFI of (serving) cells other than the unlicensed cell isindicated by the DCI format 2_0. Furthermore, if a network configures aUE to receive a DCI format 2_0 in an unlicensed (serving) cell, thenetwork may not be allowed to configure that SFI of (serving) cellsother than the licensed cell is indicated by the DCI format 2_0.

In one embodiment, if a network configures a UE to receive a DCI format2_0 in an unlicensed (serving) cell, the network may not be allowed toconfigure that SFI of a licensed (serving) cell is indicated by the DCIformat 2_0. Furthermore, if a network configures a UE to receive a DCIformat 2_0 in a licensed cell, the network may not be allowed toconfigure that SFI of an unlicensed cell is indicated by the DCI format2_0. A network may not be allowed to transmit a DCI format 2_0 in alicensed cell indicating slot format for an unlicensed cell.

In one embodiment, a UE may be configured to receive a downlink controlinformation (DCI) indicating slot format indication (SFI) for one ormore than one (serving) cells. If the UE is configured to receive theDCI in a licensed cell, the UE may not expect the DCI indicates SFI foran unlicensed cell. Also, if the UE is configured to receive the DCI inan unlicensed cell, the UE may not expect the DCI indicates a SFI for aserving cell not operated in unlicensed spectrum. Furthermore, if the UEis configured to receive the DCI in an unlicensed cell, the UE may notexpect the DCI indicates a SFI for a serving cell other than theunlicensed (serving) cell.

All or some of above embodiments can be formed to a new embodiment.

FIG. 25 is a flow chart 2500 according to one exemplary embodiment fromthe perspective of a UE. In step 2505, the UE communicates with a firstcell and a second cell. In step 2510, the UE is configured to receive aDCI on periodic monitoring occasion in the first cell, wherein the DCIindicates a first SFI for the first cell and a second SFI for the secondcell. In step 2515, if the UE receives the DCI in the first cell beforethe UE detects or receives a channel indicator, the UE discards orignores the second SFI.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) tocommunicate with a first cell and a second cell, (ii) to be configuredto receive a DCI on periodic monitoring occasion in the first cell,wherein the DCI indicates a first SFI for the first cell and a secondSFI for the second cell, and (iii) to discard or ignore the second SFIif the UE receives the DCI in the first cell before the UE detects orreceives a channel indicator. Furthermore, the CPU 308 can execute theprogram code 312 to perform all of the above-described actions and stepsor others described herein.

FIG. 26 is a flow chart 2600 according to one exemplary embodiment fromthe perspective of a UE. In step 2605, the UE communicates with a firstcell and a second cell. In step 2610, the UE is configured to receive aDCI on periodic monitoring occasion in the first cell, wherein the DCIindicates a SFI for the first cell and a second SFI for the second cell.In step 2615, if the UE receives the DCI in the first cell before the UEdetects or receives a channel indicator, the UE buffers the second SFIuntil the UE receives the channel indicator.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a UE,the device 300 includes a program code 312 stored in the memory 310. TheCPU 308 could execute program code 312 to enable the UE (i) tocommunicate with a first cell and a second cell, (ii) to be configuredto receive a DCI on periodic monitoring occasion in the first cell,wherein the DCI indicates a SFI for the first cell and a second SFI forthe second cell, and (iii) to buffer the second SFI until the UEreceives the channel indicator if the UE receives the DCI in the firstcell before the UE detects or receives a channel indicator. Furthermore,the CPU 308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

In the context of the embodiments illustrated in FIGS. 25 and 26 anddescribed above, in one embodiment, the UE could apply the second SFIstarting from OFDM symbol where the UE receives the channel indicatoruntil an available SFI monitoring occasion. The available SFI monitoringoccasion could be a SFI monitoring occasion within a channel occupationtime. Slot format values in the second SFI could indicate slot format ofone or more than one slot starting from the slot where the UE receivesthe DCI. The SFI could indicate a slot combination for a serving cell.

In one embodiment, a slot combination could comprise one or more slotformat values. A slot format value could indicate slot format of a slot,and/or transmitted direction or functionality of each OFDM symbols in aslot. The DCI could be DCI format 2_0.

In one embodiment, the first cell could be a licensed cell or anunlicensed cell, and the second cell could be a licensed cell or anunlicensed cell. The SFI received in a monitoring occasion of the DCIcould at least indicate slot format of slots from the slot aligningbeginning of the monitoring occasion of the DCI to next monitoringoccasion of the DCI. The channel indicator could indicate starting of anetwork's COT. The channel indicator could also indicate starting of atime duration.

In one embodiment, the UE may assume that a network's COT starts fromOFDM symbol where the UE receives the channel indicator. Furthermore, anetwork's COT could start earlier than the network transmits the channelindicator. The channel indicator could be a reference signal, and (oneof) DMRS of CORESET, a common signal, and a group common signal. Thenetwork could transmit the channel indicator if or after the networkoccupied the channel, or if or after the network performs channel accessprocedure or LBT schemes successfully.

FIG. 27 is a flow chart 2700 according to one exemplary embodiment fromthe perspective of a network. In step 2705, the network serves a firstcell and a second cell. In step 2710, the network configures a UE toreceive a DCI on periodic monitoring occasion on the first cell, whereinthe DCI indicates a first SFI for the first cell and a second SFI forthe second cell. In step 2715, if the network transmits SFI for anunlicensed cell in a licensed cell before performing channel accessprocedure or LBT scheme successfully in the unlicensed cell, the networkis not allowed to indicate slot format value(s) for the unlicensedserving cell other than a particular slot format value in the SFI.

In one embodiment, the particular slot format value could indicate oneslot format value 255 or a slot format value intended for slot structurein unlicensed spectrum. Furthermore, for an unlicensed cell, the UE maynot expect to receive SFI indicating a slot format value other than theparticular slot format value before the UE receives a channel indicatorand/or detects or be indicated the channel occupation time. In addition,if the network transmits the DCI on the first cell before the networkperforms channel access procedure or LBT scheme successfully, thenetwork is not allowed to transmit the second SFI indicating slot formatvalue(s) other than the particular slot format value.

In one embodiment, whether the UE applies the SFI for an unlicensed cellcould be determined based on a channel indicator. Before the UE receivesthe channel indicator, the UE may not apply SFI for the unlicensed cell.Furthermore, before the UE receives the channel indicator, the UE maynot apply slot format value 255 for the unlicensed cell. In addition, ifor after the UE receives the channel indicator, the UE could apply slotformat value 255 for the unlicensed cell.

In one embodiment, a SFI could indicate a slot combination for a servingcell. A slot combination could comprise one or more than one slot formatvalue. A slot format value could indicate slot format of each OFDMsymbol in a slot, and/or could indicate transmitted direction orfunctionality of each OFDM symbol in a slot. The DCI could be DCI format2_0.

In one embodiment, the first cell could be a licensed cell or anunlicensed cell, and the second cell could be a licensed cell or anunlicensed cell. The SFI received in a monitoring occasion of the DCIcould at least indicate slot format of slots from the slot aligningbeginning of the monitoring occasion of the DCI to next monitoringoccasion of the DCI. The channel indicator could indicate starting of anetwork's channel occupancy time (COT). Furthermore, the channelindicator could indicate starting of a time duration.

In one embodiment, the UE may assume a network's COT starts from OFDMsymbol where the UE receives the channel indicator. A network's COTcould start earlier than the network transmits the channel indicator.The channel indicator could be a reference signal, and (one of) DMRS ofCORESET, a common signal, and a group common signal. The network couldtransmit the channel indicator if or after the network occupied thechannel, or if or after the network performs channel access procedure orLBT schemes successfully.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network(i) to serve a first cell and a second cell, (ii) to configure a UE toreceive a DCI on periodic monitoring occasion on the first cell, whereinthe DCI indicates a first SFI for the first cell and a second SFI forthe second cell, and (iii) to not be allowed to indicate slot formatvalue(s) for the unlicensed serving cell other than a particular slotformat value in the SFI if the network transmits SFI for an unlicensedcell in a licensed cell before performing channel access procedure orLBT scheme successfully in the unlicensed cell. Furthermore, the CPU 308can execute the program code 312 to perform all of the above-describedactions and steps or others described herein.

FIG. 28 is a flow chart 2800 according to one exemplary embodiment fromthe perspective of a network. In step 2805, the network indicates SFIfor one or more than one serving cells by a DCI. In step 2810, if thenetwork transmits the DCI in a licensed cell, the network does notconfigure or indicate an SFI for an unlicensed cell in the DCI. In step2815, if the network transmits the DCI in an unlicensed cell, thenetwork is not allowed to indicate an SFI for a serving cell notoperated in an unlicensed spectrum.

In one embodiment, the network may not be allowed to configure alicensed serving cell indicating or transmitting an SFI for anunlicensed cell. Furthermore, the network may not be allowed toconfigure an unlicensed serving cell indicating or transmitting an SFIfor a serving cell not operated in unlicensed spectrum. In addition, thenetwork may not be allowed to transmit a DCI format 2_0 in a licensedcell indicating slot format for an unlicensed cell.

In one embodiment, if a network configures a UE to receive a DCI format2_0 in an unlicensed serving cell, the network may not be allowed toconfigure SFI of serving cells other than the unlicensed cell isindicated by the DCI format 2_0. Furthermore, if a network configures aUE to receive a DCI format 2_0 in an unlicensed serving cell, thenetwork may not be allowed to configure SFI of (serving) cells otherthan the licensed cell is indicated by the DCI format 2_0.

In one embodiment, the SFI could indicate a slot combination for aserving cell. A slot combination could comprise one or more than oneslot format value. A slot format value could indicate slot format of aslot, and/or transmitted direction or functionality of each OFDM symbolsin a slot. The DCI could be DCI format 2_0. The SFI received in amonitoring occasion of the DCI could at least indicate slot format ofslots from the slot aligning beginning of the monitoring occasion of theDCI to next monitoring occasion of the DCI.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork, the device 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the network(i) to indicate SFI for one or more than one serving cells by a DCI,(ii) to not be configured or indicate an SFI for an unlicensed cell inthe DCI if the network transmits the DCI in a licensed cell, and (iii)to not be allowed to indicate an SFI for a serving cell not operated inan unlicensed spectrum if the network transmits the DCI in an unlicensedcell. Furthermore, the CPU 308 can execute the program code 312 toperform all of the above-described actions and steps or others describedherein.

Various aspects of the disclosure have been described above. It shouldbe apparent that the teachings herein could be embodied in a widevariety of forms and that any specific structure, function, or bothbeing disclosed herein is merely representative. Based on the teachingsherein one skilled in the art should appreciate that an aspect disclosedherein could be implemented independently of any other aspects and thattwo or more of these aspects could be combined in various ways. Forexample, an apparatus could be implemented or a method could bepracticed using any number of the aspects set forth herein. In addition,such an apparatus could be implemented or such a method could bepracticed using other structure, functionality, or structure andfunctionality in addition to or other than one or more of the aspectsset forth herein. As an example of some of the above concepts, in someaspects concurrent channels could be established based on pulserepetition frequencies. In some aspects concurrent channels could beestablished based on pulse position or offsets. In some aspectsconcurrent channels could be established based on time hoppingsequences. In some aspects concurrent channels could be establishedbased on pulse repetition frequencies, pulse positions or offsets, andtime hopping sequences.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, processors, means, circuits, and algorithmsteps described in connection with the aspects disclosed herein may beimplemented as electronic hardware (e.g., a digital implementation, ananalog implementation, or a combination of the two, which may bedesigned using source coding or some other technique), various forms ofprogram or design code incorporating instructions (which may be referredto herein, for convenience, as “software” or a “software module”), orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentdisclosure.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented within or performed by an integrated circuit (“IC”), anaccess terminal, or an access point. The IC may comprise a generalpurpose processor, a digital signal processor (DSP), an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, electrical components, opticalcomponents, mechanical components, or any combination thereof designedto perform the functions described herein, and may execute codes orinstructions that reside within the IC, outside of the IC, or both. Ageneral purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module (e.g., including executable instructions and relateddata) and other data may reside in a data memory such as RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of computer-readablestorage medium known in the art. A sample storage medium may be coupledto a machine such as, for example, a computer/processor (which may bereferred to herein, for convenience, as a “processor”) such theprocessor can read information (e.g., code) from and write informationto the storage medium. A sample storage medium may be integral to theprocessor. The processor and the storage medium may reside in an ASIC.The ASIC may reside in user equipment. In the alternative, the processorand the storage medium may reside as discrete components in userequipment. Moreover, in some aspects any suitable computer-programproduct may comprise a computer-readable medium comprising codesrelating to one or more of the aspects of the disclosure. In someaspects a computer program product may comprise packaging materials.

While the invention has been described in connection with variousaspects, it will be understood that the invention is capable of furthermodifications. This application is intended to cover any variations,uses or adaptation of the invention following, in general, theprinciples of the invention, and including such departures from thepresent disclosure as come within the known and customary practicewithin the art to which the invention pertains.

What is claimed is:
 1. A method for a User Equipment (UE), comprising:receiving configuration of a first serving cell and configuration of asecond serving cell from a network, wherein the first serving cell is inlicensed spectrum and the second serving cell is in unlicensed spectrum;receiving configuration indicating the UE to monitor and/or receive aDownlink Control Information (DCI) periodically in the first servingcell, wherein the DCI indicates a first Slot Format Indication (SFI) forthe first serving cell and a second SFI for the second serving cell; andignoring performing configured physical channel and/or Reference Signal(RS) reception on at least one symbol, indicated by the second SFI asflexible, on the second serving cell if the DCI is received outside achannel occupancy time for the second serving cell.
 2. The method ofclaim 1, further including discarding the second SFI indicated in theDCI if the DCI is received outside the channel occupancy time for thesecond serving cell.
 3. The method of claim 1, wherein the UE ignoringthe second SFI indicated in the DCI comprises that the UE does not applythe second SFI for the second serving cell.
 4. The method of claim 1,wherein the UE detects or is indicated that the network starts thechannel occupancy time by receiving a channel indicator.
 5. The methodof claim 4, wherein the channel indicator is Demodulation ReferenceSignal (DMRS) of a Control Resource Set (CORESET).
 6. The method ofclaim 4, wherein the channel indicator is a common signal or a groupcommon signal.
 7. The method of claim 4, wherein the channel indicatoris transmitted by the network after or in response to the networkoccupying an unlicensed channel.
 8. The method of claim 4, wherein thechannel indicator is transmitted by the network after or in response tothe network performing a channel access procedure successfully.
 9. AUser Equipment (UE), comprising: a memory; and a processor operativelycoupled to the memory, wherein the processor is configured to executeprogram code to: receive configuration of a first serving cell andconfiguration of a second serving cell from a network, wherein the firstserving cell is in licensed spectrum and the second serving cell is inunlicensed spectrum; receive configuration indicating the UE to monitorand/or receive a Downlink Control Information (DCI) periodically in thefirst serving cell, wherein the DCI indicates a first Slot FormatIndication (SFI) for the first serving cell and a second SFI for thesecond serving cell; and ignore performing configured physical channeland/or Reference Signal (RS) reception on at least one symbol, indicatedby the second SFI as flexible, on the second serving cell if the DCI isreceived outside a channel occupancy time for the second serving cell.10. The UE of claim 9, wherein the processor is further configured toexecute program code to discard the second SFI indicated in the DCI ifthe DCI is received outside the channel occupancy time for the secondserving cell.
 11. The UE of claim 9, wherein the UE ignoring the secondSFI indicated in the DCI comprises that the UE does not apply the secondSFI for the second serving cell.
 12. The UE of claim 9, wherein the UEdetects or is indicated that the network starts the channel occupancytime by receiving a channel indicator.
 13. The UE of claim 12, whereinthe channel indicator is Demodulation Reference Signal (DMRS) of aControl Resource Set (CORESET).
 14. The UE of claim 12, wherein thechannel indicator is a common signal or a group common signal.
 15. TheUE of claim 12, wherein the channel indicator is transmitted by thenetwork after or in response to the network occupying an unlicensedchannel.
 16. The UE of claim 12, wherein the channel indicator istransmitted by the network after or in response to the networkperforming a channel access procedure successfully.